{"id":3095,"date":"2026-09-24T09:00:00","date_gmt":"2026-09-24T09:00:00","guid":{"rendered":"https:\/\/otus.ru\/journal\/?p=3095"},"modified":"2026-09-25T15:29:57","modified_gmt":"2026-09-25T15:29:57","slug":"obektno-orientirovannoe-programmirovanie-v-javascript-prototipy","status":"publish","type":"post","link":"https:\/\/otus.ru\/journal\/obektno-orientirovannoe-programmirovanie-v-javascript-prototipy\/","title":{"rendered":"\u041e\u041e\u041f \u0432 JavaScript: \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u044b, \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u044b \u0438 \u043a\u043b\u0430\u0441\u0441\u044b"},"content":{"rendered":"

\u041e\u041e\u041f \u0432 JavaScript<\/strong> — \u044d\u0442\u043e \u0441\u043f\u043e\u0441\u043e\u0431 \u0441\u0442\u0440\u043e\u0438\u0442\u044c \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0443 \u0438\u0437 \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u0432, \u0443 \u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u0435\u0441\u0442\u044c \u0434\u0430\u043d\u043d\u044b\u0435 (\u0441\u0432\u043e\u0439\u0441\u0442\u0432\u0430) \u0438 \u043f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u0435 (\u043c\u0435\u0442\u043e\u0434\u044b). \u0412 \u043e\u0442\u043b\u0438\u0447\u0438\u0435 \u043e\u0442 Java \u0438\u043b\u0438 C#, \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0435 \u0432 JS \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043d\u043e\u0435<\/strong>: \u043e\u0431\u044a\u0435\u043a\u0442 \u0441\u0441\u044b\u043b\u0430\u0435\u0442\u0441\u044f \u043d\u0430 \u0434\u0440\u0443\u0433\u043e\u0439 \u043e\u0431\u044a\u0435\u043a\u0442-\u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u0438 \u0431\u0435\u0440\u0435\u0442 \u0443 \u043d\u0435\u0433\u043e \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u044e\u0449\u0438\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u0430. \u041a\u043b\u044e\u0447\u0435\u0432\u043e\u0435 \u0441\u043b\u043e\u0432\u043e class<\/code> \u043f\u043e\u044f\u0432\u0438\u043b\u043e\u0441\u044c \u0432 ES2015 \u0438 \u0434\u0430\u0435\u0442 \u043f\u0440\u0438\u0432\u044b\u0447\u043d\u044b\u0439 \u0441\u0438\u043d\u0442\u0430\u043a\u0441\u0438\u0441, \u043d\u043e \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u044b \u043a\u043b\u0430\u0441\u0441\u0430 \u0432\u0441\u0435 \u0440\u0430\u0432\u043d\u043e \u0441\u0432\u044f\u0437\u0430\u043d\u044b \u0447\u0435\u0440\u0435\u0437 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u044b.<\/p>\n

\n

\u0421\u043e\u0434\u0435\u0440\u0436\u0430\u043d\u0438\u0435<\/strong><\/p>\n

    \n
  1. \u041c\u0438\u043d\u0438-\u0441\u043b\u043e\u0432\u0430\u0440\u044c: \u0442\u0440\u0438 \u0440\u0430\u0437\u043d\u044b\u0445 \u00ab\u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0430\u00bb<\/a><\/li>\n
  2. \u041c\u0438\u043d\u0438\u043c\u0430\u043b\u044c\u043d\u044b\u0439 \u043f\u0440\u0438\u043c\u0435\u0440: \u043a\u043b\u0430\u0441\u0441, \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0435 \u0438 \u0446\u0435\u043f\u043e\u0447\u043a\u0430<\/a><\/li>\n
  3. \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 \u0446\u0435\u043f\u043e\u0447\u043a\u0430 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u0432<\/a><\/li>\n
  4. \u0427\u0435\u0442\u044b\u0440\u0435 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u0441\u043e\u0437\u0434\u0430\u0442\u044c \u043e\u0431\u044a\u0435\u043a\u0442<\/a><\/li>\n
  5. \u0424\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440: \u0447\u0442\u043e \u0434\u0435\u043b\u0430\u0435\u0442 new<\/code><\/a><\/li>\n
  6. \u041a\u043b\u0430\u0441\u0441\u044b: extends, super, \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u044b\u0435 \u0438 \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0435 \u043f\u043e\u043b\u044f<\/a><\/li>\n
  7. \u041a\u0430\u043a extends<\/code> \u0432\u044b\u0433\u043b\u044f\u0434\u0438\u0442 \u0431\u0435\u0437 \u043a\u043b\u0430\u0441\u0441\u043e\u0432<\/a><\/li>\n
  8. \u0422\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438<\/a><\/li>\n
  9. \u0412\u044b\u0432\u043e\u0434\u044b<\/a><\/li>\n
  10. \u0413\u0434\u0435 \u043f\u0440\u0438\u043c\u0435\u043d\u044f\u0435\u0442\u0441\u044f \/ \u0441\u0432\u044f\u0437\u044c \u0441 \u043f\u0440\u0430\u043a\u0442\u0438\u043a\u043e\u0439<\/a><\/li>\n
  11. FAQ<\/a><\/li>\n<\/ol>\n<\/div>\n

    \u041d\u0438\u0436\u0435 — \u043a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 \u0446\u0435\u043f\u043e\u0447\u043a\u0430 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u0432, \u0447\u0435\u0442\u044b\u0440\u0435 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u0441\u043e\u0437\u0434\u0430\u0432\u0430\u0442\u044c \u043e\u0431\u044a\u0435\u043a\u0442\u044b (\u0444\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440, class<\/code>, Object.create<\/code>, \u0444\u0430\u0431\u0440\u0438\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f), \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0435 \u0447\u0435\u0440\u0435\u0437 extends<\/code> \u0438 \u0447\u0430\u0441\u0442\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 \u0441 this<\/code> \u0438 new<\/code>. \u0412\u0441\u0435 \u043f\u0440\u0438\u043c\u0435\u0440\u044b \u043f\u0440\u043e\u0432\u0435\u0440\u0435\u043d\u044b \u0432 Node.js 24.21 (24 LTS), \u0432\u044b\u0432\u043e\u0434 \u0432\u0437\u044f\u0442 \u0438\u0437 \u0440\u0435\u0430\u043b\u044c\u043d\u043e\u0433\u043e \u0437\u0430\u043f\u0443\u0441\u043a\u0430.<\/p>\n

    \u041c\u0438\u043d\u0438-\u0441\u043b\u043e\u0432\u0430\u0440\u044c: \u0442\u0440\u0438 \u0440\u0430\u0437\u043d\u044b\u0445 \u00ab\u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0430\u00bb<\/h2>\n

    \u0421\u043b\u043e\u0432\u043e \u00ab\u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u00bb \u0432 JS \u043e\u0431\u043e\u0437\u043d\u0430\u0447\u0430\u0435\u0442 \u0442\u0440\u0438 \u0440\u0430\u0437\u043d\u044b\u0435 \u0432\u0435\u0449\u0438. \u0418\u0445 \u043f\u0443\u0442\u0430\u044e\u0442 \u0447\u0430\u0449\u0435 \u0432\u0441\u0435\u0433\u043e, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 \u0441\u0440\u0430\u0437\u0443 \u0440\u0430\u0437\u0432\u0435\u0434\u0435\u043c:<\/p>\n\n\n\n\n\n\n\n
    \u0422\u0435\u0440\u043c\u0438\u043d<\/th>\n\u0427\u0442\u043e \u044d\u0442\u043e<\/th>\n\u041a\u0430\u043a \u043f\u043e\u043b\u0443\u0447\u0438\u0442\u044c<\/th>\n<\/tr>\n<\/thead>\n
    \u0441\u043a\u0440\u044b\u0442\u0430\u044f \u0441\u0441\u044b\u043b\u043a\u0430 Prototype<\/td>\n\u0432\u043d\u0443\u0442\u0440\u0435\u043d\u043d\u044f\u044f \u0441\u0441\u044b\u043b\u043a\u0430 \u043e\u0431\u044a\u0435\u043a\u0442\u0430 \u043d\u0430 \u0435\u0433\u043e \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f (\u0432 \u0441\u043f\u0435\u0446\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438 — \u0441\u043b\u043e\u0442 Prototype \u0432 \u0434\u0432\u043e\u0439\u043d\u044b\u0445 \u043a\u0432\u0430\u0434\u0440\u0430\u0442\u043d\u044b\u0445 \u0441\u043a\u043e\u0431\u043a\u0430\u0445)<\/td>\nObject.getPrototypeOf(obj)<\/code><\/td>\n<\/tr>\n
    F.prototype<\/code><\/td>\n\u043e\u0431\u044b\u0447\u043d\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0444\u0443\u043d\u043a\u0446\u0438\u0438-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u0430 \u0438\u043b\u0438 \u043a\u043b\u0430\u0441\u0441\u0430: \u043e\u0431\u044a\u0435\u043a\u0442, \u043a\u043e\u0442\u043e\u0440\u044b\u0439 \u0441\u0442\u0430\u043d\u0435\u0442 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u043c \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u043e\u0432, \u0441\u043e\u0437\u0434\u0430\u043d\u043d\u044b\u0445 \u0447\u0435\u0440\u0435\u0437 new F()<\/code><\/td>\nF.prototype<\/code><\/td>\n<\/tr>\n
    __proto__<\/code><\/td>\n\u0443\u0441\u0442\u0430\u0440\u0435\u0432\u0448\u0438\u0439 \u0430\u043a\u0441\u0435\u0441\u0441\u043e\u0440 \u043a \u0441\u043a\u0440\u044b\u0442\u043e\u0439 \u0441\u0441\u044b\u043b\u043a\u0435, \u043e\u0441\u0442\u0430\u0432\u043b\u0435\u043d \u0434\u043b\u044f \u0441\u043e\u0432\u043c\u0435\u0441\u0442\u0438\u043c\u043e\u0441\u0442\u0438<\/td>\n\u0432 \u043d\u043e\u0432\u043e\u043c \u043a\u043e\u0434\u0435 \u043d\u0435 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u044c<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    \u0426\u0435\u043f\u043e\u0447\u043a\u0430 \u043d\u0430 \u043e\u0434\u043d\u043e\u043c \u043f\u0440\u0438\u043c\u0435\u0440\u0435: rex<\/code> -> Dog.prototype<\/code> -> Animal.prototype<\/code> -> Object.prototype<\/code> -> null<\/code>.<\/p>\n

    \u041c\u0438\u043d\u0438\u043c\u0430\u043b\u044c\u043d\u044b\u0439 \u043f\u0440\u0438\u043c\u0435\u0440: \u043a\u043b\u0430\u0441\u0441, \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0435 \u0438 \u0446\u0435\u043f\u043e\u0447\u043a\u0430<\/h2>\n
    class<\/span> <\/span>Animal<\/span> {<\/span>\n  <\/span>constructor<\/span>(<\/span>name<\/span>) {<\/span>\n    <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;            <\/span>\/\/ \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u0430<\/span>\n  }<\/span>\n  <\/span>speak<\/span>() {                      <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u043f\u043e\u043f\u0430\u0434\u0430\u0435\u0442 \u0432 Animal.prototype<\/span>\n    <\/span>return<\/span> <\/span>`${<\/span>this<\/span>.<\/span>name<\/span>} \u0438\u0437\u0434\u0430\u0435\u0442 \u0437\u0432\u0443\u043a`<\/span>;<\/span>\n  }<\/span>\n}<\/span>\n\nclass<\/span> <\/span>Dog<\/span> <\/span>extends<\/span> <\/span>Animal<\/span> {<\/span>\n  <\/span>speak<\/span>() {                      <\/span>\/\/ \u043f\u0435\u0440\u0435\u043e\u043f\u0440\u0435\u0434\u0435\u043b\u0435\u043d\u0438\u0435: Dog.prototype.speak<\/span>\n    <\/span>return<\/span> <\/span>`${<\/span>super<\/span>.<\/span>speak<\/span>()<\/span>} \u0438 \u043b\u0430\u0435\u0442`<\/span>;<\/span>\n  }<\/span>\n}<\/span>\n\nconst<\/span> <\/span>rex<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Dog<\/span>(<\/span>\"\u0420\u0435\u043a\u0441\"<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>rex<\/span>.<\/span>speak<\/span>());<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>hasOwn<\/span>(<\/span>rex<\/span>, <\/span>\"name\"<\/span>), <\/span>Object<\/span>.<\/span>hasOwn<\/span>(<\/span>rex<\/span>, <\/span>\"speak\"<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>getPrototypeOf<\/span>(<\/span>rex<\/span>) <\/span>===<\/span> <\/span>Dog<\/span>.<\/span>prototype<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>getPrototypeOf<\/span>(<\/span>Dog<\/span>.<\/span>prototype<\/span>) <\/span>===<\/span> <\/span>Animal<\/span>.<\/span>prototype<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>getPrototypeOf<\/span>(<\/span>Animal<\/span>.<\/span>prototype<\/span>) <\/span>===<\/span> <\/span>Object<\/span>.<\/span>prototype<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>getPrototypeOf<\/span>(<\/span>Object<\/span>.<\/span>prototype<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>typeof<\/span> <\/span>Animal<\/span>, <\/span>rex<\/span> <\/span>instanceof<\/span> <\/span>Animal<\/span>);<\/span><\/code><\/pre>\n
    \u0412\u044b\u0432\u043e\u0434:<\/p>\n
    \u0420\u0435\u043a\u0441 \u0438\u0437\u0434\u0430\u0435\u0442 \u0437\u0432\u0443\u043a \u0438 \u043b\u0430\u0435\u0442\ntrue false\ntrue\ntrue\ntrue\nnull\nfunction true\n<\/code><\/pre>\n
    \u0427\u0442\u043e \u0437\u0434\u0435\u0441\u044c \u0432\u0438\u0434\u043d\u043e. \u0421\u0432\u043e\u0439\u0441\u0442\u0432\u043e name<\/code> \u043b\u0435\u0436\u0438\u0442 \u0432 \u0441\u0430\u043c\u043e\u043c \u043e\u0431\u044a\u0435\u043a\u0442\u0435, \u0430 \u043c\u0435\u0442\u043e\u0434\u0430 speak<\/code> \u0432 \u043d\u0435\u043c \u043d\u0435\u0442: \u043e\u043d \u0445\u0440\u0430\u043d\u0438\u0442\u0441\u044f \u0432 Dog.prototype<\/code> \u0438 \u043e\u0434\u0438\u043d \u043d\u0430 \u0432\u0441\u0435 \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u044b. typeof Animal<\/code> \u0434\u0430\u0435\u0442 function<\/code> — \u043a\u043b\u0430\u0441\u0441 \u0432 JS \u043f\u043e-\u043f\u0440\u0435\u0436\u043d\u0435\u043c\u0443 \u0444\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440. \u0426\u0435\u043f\u043e\u0447\u043a\u0430 \u0437\u0430\u043a\u0430\u043d\u0447\u0438\u0432\u0430\u0435\u0442\u0441\u044f \u043d\u0430 null<\/code>: \u0443 Object.prototype<\/code> \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0430 \u043d\u0435\u0442.<\/p>\n
    \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 \u0446\u0435\u043f\u043e\u0447\u043a\u0430 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u0432<\/h2>\n
    \u041a\u043e\u0433\u0434\u0430 \u0432\u044b \u0447\u0438\u0442\u0430\u0435\u0442\u0435 obj.prop<\/code>, \u0434\u0432\u0438\u0436\u043e\u043a \u0438\u0449\u0435\u0442 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0442\u0430\u043a:<\/p>\n
      \n
    1. \u0415\u0441\u0442\u044c \u043b\u0438 \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e prop<\/code> \u0443 obj<\/code>? \u0415\u0441\u043b\u0438 \u0434\u0430 — \u0432\u0435\u0440\u043d\u0443\u0442\u044c \u0435\u0433\u043e.<\/li>\n
    2. \u041d\u0435\u0442 — \u043f\u0435\u0440\u0435\u0439\u0442\u0438 \u043a Object.getPrototypeOf(obj)<\/code> \u0438 \u043f\u043e\u0432\u0442\u043e\u0440\u0438\u0442\u044c \u043f\u043e\u0438\u0441\u043a \u0442\u0430\u043c.<\/li>\n
    3. \u0414\u043e\u0448\u043b\u0438 \u0434\u043e null<\/code> \u0438 \u043d\u0435 \u043d\u0430\u0448\u043b\u0438 — \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 undefined<\/code> (\u043e\u0448\u0438\u0431\u043a\u0438 \u043d\u0435\u0442).<\/li>\n<\/ol>\n
      \u042d\u0442\u043e \u043f\u0440\u0430\u0432\u0438\u043b\u043e \u0434\u043b\u044f \u0447\u0442\u0435\u043d\u0438\u044f. \u0417\u0430\u043f\u0438\u0441\u044c \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 \u0438\u043d\u0430\u0447\u0435: obj.prop = value<\/code> \u043e\u0431\u044b\u0447\u043d\u043e \u0441\u043e\u0437\u0434\u0430\u0435\u0442 \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0443 obj<\/code> \u0438 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u043d\u0435 \u043c\u0435\u043d\u044f\u0435\u0442 (\u0438\u0441\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u044f — \u0441\u0435\u0442\u0442\u0435\u0440 \u0438\u043b\u0438 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0442\u043e\u043b\u044c\u043a\u043e \u0434\u043b\u044f \u0447\u0442\u0435\u043d\u0438\u044f \u0432 \u0446\u0435\u043f\u043e\u0447\u043a\u0435).<\/p>\n
      const<\/span> <\/span>base<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>kind<\/span>:<\/span> <\/span>\"base\"<\/span>,<\/span>\n  <\/span>greet<\/span>() { <\/span>return<\/span> <\/span>`\u043f\u0440\u0438\u0432\u0435\u0442, \u044f ${<\/span>this<\/span>.<\/span>kind<\/span>}`<\/span>; },<\/span>\n};<\/span>\nconst<\/span> <\/span>child<\/span> <\/span>=<\/span> <\/span>Object<\/span>.<\/span>create<\/span>(<\/span>base<\/span>);   <\/span>\/\/ \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f child - \u044d\u0442\u043e base<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>child<\/span>.<\/span>greet<\/span>());          <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u043d\u0430\u0439\u0434\u0435\u043d \u0432 base, this = child<\/span>\nchild<\/span>.<\/span>kind<\/span> <\/span>=<\/span> <\/span>\"child\"<\/span>;                <\/span>\/\/ \u0437\u0430\u043f\u0438\u0441\u044c \u0441\u043e\u0437\u0434\u0430\u0435\u0442 \u0421\u041e\u0411\u0421\u0422\u0412\u0415\u041d\u041d\u041e\u0415 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>child<\/span>.<\/span>greet<\/span>(), <\/span>\"|\"<\/span>, <\/span>base<\/span>.<\/span>kind<\/span>);<\/span>\ndelete<\/span> <\/span>child<\/span>.<\/span>kind<\/span>;                   <\/span>\/\/ \u0443\u0434\u0430\u043b\u0438\u043b\u0438 \u0441\u0432\u043e\u0435 - \u0441\u043d\u043e\u0432\u0430 \u0432\u0438\u0434\u0435\u043d \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>child<\/span>.<\/span>kind<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>child<\/span>.<\/span>missing<\/span>);          <\/span>\/\/ \u043d\u0435 \u043d\u0430\u0448\u043b\u0438 \u0434\u043e \u043a\u043e\u043d\u0446\u0430 \u0446\u0435\u043f\u043e\u0447\u043a\u0438<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>keys<\/span>(<\/span>child<\/span>));     <\/span>\/\/ \u0442\u043e\u043b\u044c\u043a\u043e \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u044b\u0435 \u043a\u043b\u044e\u0447\u0438<\/span>\nfor<\/span> (<\/span>const<\/span> <\/span>key<\/span> <\/span>in<\/span> <\/span>child<\/span>) <\/span>console<\/span>.<\/span>log<\/span>(<\/span>\"for...in:\"<\/span>, <\/span>key<\/span>); <\/span>\/\/ \u0438 \u0443\u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u043d\u044b\u0435<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434:<\/p>\n
      \u043f\u0440\u0438\u0432\u0435\u0442, \u044f base\n\u043f\u0440\u0438\u0432\u0435\u0442, \u044f child | base\nbase\nundefined\n[]\nfor...in: kind\nfor...in: greet\n<\/code><\/pre>\n
      \u0412\u0430\u0436\u043d\u0430\u044f \u0434\u0435\u0442\u0430\u043b\u044c: \u043c\u0435\u0442\u043e\u0434 \u0431\u0435\u0440\u0435\u0442\u0441\u044f \u0438\u0437 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0430, \u043d\u043e this<\/code> \u0432\u043d\u0443\u0442\u0440\u0438 \u043d\u0435\u0433\u043e — \u0442\u043e\u0442 \u043e\u0431\u044a\u0435\u043a\u0442, \u0443 \u043a\u043e\u0442\u043e\u0440\u043e\u0433\u043e \u043c\u0435\u0442\u043e\u0434 \u0432\u044b\u0437\u0432\u0430\u043b\u0438 (child<\/code>). \u041f\u043e\u044d\u0442\u043e\u043c\u0443 \u043e\u0434\u0438\u043d \u043c\u0435\u0442\u043e\u0434 \u043e\u0431\u0441\u043b\u0443\u0436\u0438\u0432\u0430\u0435\u0442 \u0432\u0441\u0435 \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u044b. \u0418 \u0432\u0442\u043e\u0440\u043e\u0435: for...in<\/code> \u043e\u0431\u0445\u043e\u0434\u0438\u0442 \u0438 \u0443\u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u043d\u044b\u0435 \u043f\u0435\u0440\u0435\u0447\u0438\u0441\u043b\u044f\u0435\u043c\u044b\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u0430, \u0430 Object.keys<\/code> — \u0442\u043e\u043b\u044c\u043a\u043e \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u044b\u0435.<\/p>\n
      \u0427\u0435\u0442\u044b\u0440\u0435 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u0441\u043e\u0437\u0434\u0430\u0442\u044c \u043e\u0431\u044a\u0435\u043a\u0442<\/h2>\n
      \u041e\u0434\u043d\u0430 \u0437\u0430\u0434\u0430\u0447\u0430 — \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044c \u0441 \u0438\u043c\u0435\u043d\u0435\u043c \u0438 \u043c\u0435\u0442\u043e\u0434\u043e\u043c greet<\/code> — \u0440\u0435\u0448\u0435\u043d\u043d\u0430\u044f \u0447\u0435\u0442\u044b\u0440\u044c\u043c\u044f \u0441\u043f\u043e\u0441\u043e\u0431\u0430\u043c\u0438:<\/p>\n
      \/\/ 1. \u0424\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440 + prototype<\/span>\nfunction<\/span> <\/span>UserF<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n}<\/span>\nUserF<\/span>.<\/span>prototype<\/span>.<\/span>greet<\/span> <\/span>=<\/span> <\/span>function<\/span> () {<\/span>\n  <\/span>return<\/span> <\/span>`\u042f ${<\/span>this<\/span>.<\/span>name<\/span>}`<\/span>;<\/span>\n};<\/span>\n\n\/\/ 2. \u041a\u043b\u0430\u0441\u0441<\/span>\nclass<\/span> <\/span>UserC<\/span> {<\/span>\n  <\/span>constructor<\/span>(<\/span>name<\/span>) {<\/span>\n    <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n  }<\/span>\n  <\/span>greet<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>`\u042f ${<\/span>this<\/span>.<\/span>name<\/span>}`<\/span>;<\/span>\n  }<\/span>\n}<\/span>\n\n\/\/ 3. \u0421\u0432\u044f\u0437\u044b\u0432\u0430\u043d\u0438\u0435 \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u0432: Object.create + init<\/span>\nconst<\/span> <\/span>UserProto<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>init<\/span>(<\/span>name<\/span>) {<\/span>\n    <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>;<\/span>\n  },<\/span>\n  <\/span>greet<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>`\u042f ${<\/span>this<\/span>.<\/span>name<\/span>}`<\/span>;<\/span>\n  },<\/span>\n};<\/span>\n\n\/\/ 4. \u0424\u0430\u0431\u0440\u0438\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/span>\nfunction<\/span> <\/span>createUser<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>return<\/span> {<\/span>\n    <\/span>greet<\/span>() {<\/span>\n      <\/span>return<\/span> <\/span>`\u042f ${<\/span>name<\/span>}`<\/span>;          <\/span>\/\/ name \u0438\u0437 \u0437\u0430\u043c\u044b\u043a\u0430\u043d\u0438\u044f, \u043d\u0435 \u0438\u0437 this<\/span>\n    },<\/span>\n  };<\/span>\n}<\/span>\n\nconst<\/span> <\/span>users<\/span> <\/span>=<\/span> [<\/span>\n  <\/span>new<\/span> <\/span>UserF<\/span>(<\/span>\"\u0410\u043d\u044f\"<\/span>),<\/span>\n  <\/span>new<\/span> <\/span>UserC<\/span>(<\/span>\"\u0411\u043e\u0440\u044f\"<\/span>),<\/span>\n  <\/span>Object<\/span>.<\/span>create<\/span>(<\/span>UserProto<\/span>).<\/span>init<\/span>(<\/span>\"\u0412\u0438\u043a\u0430\"<\/span>),<\/span>\n  <\/span>createUser<\/span>(<\/span>\"\u0413\u043e\u0448\u0430\"<\/span>),<\/span>\n];<\/span>\nfor<\/span> (<\/span>const<\/span> <\/span>u<\/span> <\/span>of<\/span> <\/span>users<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>u<\/span>.<\/span>greet<\/span>(), <\/span>\"| greet \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435:\"<\/span>, <\/span>!<\/span>Object<\/span>.<\/span>hasOwn<\/span>(<\/span>u<\/span>, <\/span>\"greet\"<\/span>));<\/span>\n}<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>new<\/span> <\/span>UserF<\/span>(<\/span>\"a\"<\/span>).<\/span>greet<\/span> <\/span>===<\/span> <\/span>new<\/span> <\/span>UserF<\/span>(<\/span>\"b\"<\/span>).<\/span>greet<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>createUser<\/span>(<\/span>\"a\"<\/span>).<\/span>greet<\/span> <\/span>===<\/span> <\/span>createUser<\/span>(<\/span>\"b\"<\/span>).<\/span>greet<\/span>);<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434:<\/p>\n
      \u042f \u0410\u043d\u044f | greet \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435: true\n\u042f \u0411\u043e\u0440\u044f | greet \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435: true\n\u042f \u0412\u0438\u043a\u0430 | greet \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435: true\n\u042f \u0413\u043e\u0448\u0430 | greet \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435: false\ntrue\nfalse\n<\/code><\/pre>\n
      \u041f\u0435\u0440\u0432\u044b\u0435 \u0442\u0440\u0438 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u043a\u043b\u0430\u0434\u0443\u0442 greet<\/code> \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f — \u043e\u0434\u043d\u0430 \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043d\u0430 \u0432\u0441\u0435 \u043e\u0431\u044a\u0435\u043a\u0442\u044b. \u0424\u0430\u0431\u0440\u0438\u043a\u0430 \u0432 \u0442\u0430\u043a\u043e\u043c \u0432\u0438\u0434\u0435 \u0441\u043e\u0437\u0434\u0430\u0435\u0442 \u043d\u043e\u0432\u0443\u044e \u0444\u0443\u043d\u043a\u0446\u0438\u044e \u0434\u043b\u044f \u043a\u0430\u0436\u0434\u043e\u0433\u043e \u043e\u0431\u044a\u0435\u043a\u0442\u0430: \u044d\u0442\u043e \u0446\u0435\u043d\u0430 \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0441\u0442\u0438 \u0447\u0435\u0440\u0435\u0437 \u0437\u0430\u043c\u044b\u043a\u0430\u043d\u0438\u0435 (\u0438\u043c\u044f \u043d\u0435\u043b\u044c\u0437\u044f \u0438\u0437\u043c\u0435\u043d\u0438\u0442\u044c \u0441\u043d\u0430\u0440\u0443\u0436\u0438). \u0414\u043b\u044f \u0441\u043e\u0442\u0435\u043d \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u0432 \u0440\u0430\u0437\u043d\u0438\u0446\u0430 \u0432 \u043f\u0430\u043c\u044f\u0442\u0438 \u043d\u0435\u0437\u0430\u043c\u0435\u0442\u043d\u0430, \u0434\u043b\u044f \u043c\u0438\u043b\u043b\u0438\u043e\u043d\u043e\u0432 — \u0443\u0436\u0435 \u043c\u043e\u0436\u0435\u0442 \u0431\u044b\u0442\u044c \u0437\u0430\u043c\u0435\u0442\u043d\u0430.<\/p>\n\n\n\n\n\n\n\n\n
      \u0421\u043f\u043e\u0441\u043e\u0431<\/th>\n\u041d\u0443\u0436\u0435\u043d new<\/code><\/th>\n\u041c\u0435\u0442\u043e\u0434\u044b \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435<\/th>\n\u041f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0441\u0442\u044c<\/th>\n\u041a\u043e\u0433\u0434\u0430 \u0431\u0440\u0430\u0442\u044c<\/th>\n<\/tr>\n<\/thead>\n
      \u0424\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440<\/td>\n\u0434\u0430<\/td>\n\u0447\u0435\u0440\u0435\u0437 F.prototype<\/code><\/td>\n\u0442\u043e\u043b\u044c\u043a\u043e \u0437\u0430\u043c\u044b\u043a\u0430\u043d\u0438\u044f<\/td>\n\u0447\u0442\u0435\u043d\u0438\u0435 \u0441\u0442\u0430\u0440\u043e\u0433\u043e \u043a\u043e\u0434\u0430 \u0438 \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a \u0434\u043e ES2015<\/td>\n<\/tr>\n
      class<\/code><\/td>\n\u0434\u0430, \u0431\u0435\u0437 \u043d\u0435\u0433\u043e \u043e\u0448\u0438\u0431\u043a\u0430<\/td>\n\u0430\u0432\u0442\u043e\u043c\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438<\/td>\n\u043f\u043e\u043b\u044f #name<\/code><\/td>\n\u043e\u0441\u043d\u043e\u0432\u043d\u043e\u0439 \u0432\u044b\u0431\u043e\u0440 \u0434\u043b\u044f \u043d\u043e\u0432\u043e\u0433\u043e \u043a\u043e\u0434\u0430<\/td>\n<\/tr>\n
      Object.create<\/code> + init<\/code><\/td>\n\u043d\u0435\u0442<\/td>\n\u043e\u0431\u044a\u0435\u043a\u0442-\u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u0437\u0430\u0434\u0430\u0435\u0442\u0441\u044f \u044f\u0432\u043d\u043e<\/td>\n\u043d\u0435\u0442 \u0432\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u043e\u0439<\/td>\n\u043a\u043e\u0433\u0434\u0430 \u043d\u0443\u0436\u0435\u043d \u044f\u0432\u043d\u044b\u0439 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u0431\u0435\u0437 \u043a\u043b\u0430\u0441\u0441\u043e\u0432<\/td>\n<\/tr>\n
      \u0424\u0430\u0431\u0440\u0438\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/td>\n\u043d\u0435\u0442<\/td>\n\u043d\u0435\u0442, \u0435\u0441\u043b\u0438 \u043d\u0435 \u0432\u0435\u0440\u043d\u0443\u0442\u044c \u043e\u0431\u044a\u0435\u043a\u0442 \u0441 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u043c<\/td>\n\u0437\u0430\u043c\u044b\u043a\u0430\u043d\u0438\u0435<\/td>\n\u043d\u0435\u0431\u043e\u043b\u044c\u0448\u0438\u0435 \u043e\u0431\u044a\u0435\u043a\u0442\u044b, \u043a\u043e\u043c\u043f\u043e\u0437\u0438\u0446\u0438\u044f, \u0441\u043a\u0440\u044b\u0442\u043e\u0435 \u0441\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u0424\u0443\u043d\u043a\u0446\u0438\u044f-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440: \u0447\u0442\u043e \u0434\u0435\u043b\u0430\u0435\u0442 new<\/code><\/h2>\n
      \u0412\u044b\u0437\u043e\u0432 new UserF(\"\u0410\u043d\u044f\")<\/code> \u0443\u043f\u0440\u043e\u0449\u0435\u043d\u043d\u043e \u0432\u044b\u043f\u043e\u043b\u043d\u044f\u0435\u0442 \u0447\u0435\u0442\u044b\u0440\u0435 \u0448\u0430\u0433\u0430: \u0441\u043e\u0437\u0434\u0430\u0435\u0442 \u043f\u0443\u0441\u0442\u043e\u0439 \u043e\u0431\u044a\u0435\u043a\u0442, \u043d\u0430\u0437\u043d\u0430\u0447\u0430\u0435\u0442 \u0435\u043c\u0443 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f UserF.prototype<\/code>, \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442 UserF<\/code> \u0441 this<\/code>, \u0443\u043a\u0430\u0437\u044b\u0432\u0430\u044e\u0449\u0438\u043c \u043d\u0430 \u043d\u043e\u0432\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442, \u0438 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u0442 \u044d\u0442\u043e\u0442 \u043e\u0431\u044a\u0435\u043a\u0442 (\u0435\u0441\u043b\u0438 \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u0441\u0430\u043c\u0430 \u043d\u0435 \u0432\u0435\u0440\u043d\u0443\u043b\u0430 \u0434\u0440\u0443\u0433\u043e\u0439 \u043e\u0431\u044a\u0435\u043a\u0442).<\/p>\n
      \u0415\u0441\u043b\u0438 new<\/code> \u0437\u0430\u0431\u044b\u0442\u044c, \u0448\u0430\u0433\u0438 1, 2 \u0438 4 \u043d\u0435 \u043f\u0440\u043e\u0438\u0441\u0445\u043e\u0434\u044f\u0442, \u0438 this<\/code> \u0443\u043a\u0430\u0437\u044b\u0432\u0430\u0435\u0442 \u043d\u0435 \u0442\u0443\u0434\u0430:<\/p>\n
      function<\/span> <\/span>UserF<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n}<\/span>\nconst<\/span> <\/span>u<\/span> <\/span>=<\/span> <\/span>UserF<\/span>(<\/span>\"\u0410\u043d\u044f\"<\/span>);           <\/span>\/\/ \u0437\u0430\u0431\u044b\u043b\u0438 new<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>u<\/span>);                   <\/span>\/\/ \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043d\u0438\u0447\u0435\u0433\u043e \u043d\u0435 \u0432\u0435\u0440\u043d\u0443\u043b\u0430<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>globalThis<\/span>.<\/span>name<\/span>);     <\/span>\/\/ \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0443\u0448\u043b\u043e \u0432 \u0433\u043b\u043e\u0431\u0430\u043b\u044c\u043d\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442<\/span>\n\nclass<\/span> <\/span>UserC<\/span> {<\/span>\n  <\/span>constructor<\/span>(<\/span>name<\/span>) {<\/span>\n    <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n  }<\/span>\n}<\/span>\ntry<\/span> {<\/span>\n  <\/span>UserC<\/span>(<\/span>\"\u0411\u043e\u0440\u044f\"<\/span>);<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>`${<\/span>e<\/span>.<\/span>name<\/span>}: ${<\/span>e<\/span>.<\/span>message<\/span>}`<\/span>);<\/span>\n}<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434 \u043f\u0440\u0438 \u0437\u0430\u043f\u0443\u0441\u043a\u0435 \u043a\u0430\u043a CommonJS-\u0441\u043a\u0440\u0438\u043f\u0442\u0430 (node file.js<\/code>, \u043d\u0435\u0441\u0442\u0440\u043e\u0433\u0438\u0439 \u0440\u0435\u0436\u0438\u043c):<\/p>\n
      undefined\n\u0410\u043d\u044f\nTypeError: Class constructor UserC cannot be invoked without 'new'\n<\/code><\/pre>\n
      \u041f\u043e\u0432\u0435\u0434\u0435\u043d\u0438\u0435 \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u0440\u0435\u0436\u0438\u043c\u0430. \u0412 \u043d\u0435\u0441\u0442\u0440\u043e\u0433\u043e\u043c \u043a\u043e\u0434\u0435 this<\/code> \u043f\u0440\u0438 \u043e\u0431\u044b\u0447\u043d\u043e\u043c \u0432\u044b\u0437\u043e\u0432\u0435 — \u0433\u043b\u043e\u0431\u0430\u043b\u044c\u043d\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442, \u0438 \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043c\u043e\u043b\u0447\u0430 \u043f\u043e\u0440\u0442\u0438\u0442 \u0435\u0433\u043e. \u0412 \u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0440\u0435\u0436\u0438\u043c\u0435 (\"use strict\"<\/code>, ES-\u043c\u043e\u0434\u0443\u043b\u0438 .mjs<\/code>, \u043a\u043e\u0434 \u0432\u043d\u0443\u0442\u0440\u0438 \u043a\u043b\u0430\u0441\u0441\u043e\u0432) this<\/code> \u0440\u0430\u0432\u0435\u043d undefined<\/code>, \u0438 \u0443\u0436\u0435 \u043f\u0435\u0440\u0432\u0430\u044f \u0441\u0442\u0440\u043e\u043a\u0430 \u043f\u0430\u0434\u0430\u0435\u0442: TypeError: Cannot set properties of undefined (setting 'name')<\/code>. \u041a\u043b\u0430\u0441\u0441 \u0437\u0430\u0449\u0438\u0449\u0435\u043d \u0432\u0441\u0435\u0433\u0434\u0430. \u0424\u0443\u043d\u043a\u0446\u0438\u044e-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440 \u043c\u043e\u0436\u043d\u043e \u0437\u0430\u0449\u0438\u0442\u0438\u0442\u044c \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u043e\u0439 new.target<\/code>:<\/p>\n
      function<\/span> <\/span>UserF<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>if<\/span> (<\/span>!new<\/span>.<\/span>target<\/span>) {<\/span>\n    <\/span>throw<\/span> <\/span>new<\/span> <\/span>TypeError<\/span>(<\/span>\"UserF \u043d\u0443\u0436\u043d\u043e \u0432\u044b\u0437\u044b\u0432\u0430\u0442\u044c \u0447\u0435\u0440\u0435\u0437 new\"<\/span>);<\/span>\n  }<\/span>\n  <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n}<\/span>\ntry<\/span> {<\/span>\n  <\/span>UserF<\/span>(<\/span>\"\u0410\u043d\u044f\"<\/span>);<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>`${<\/span>e<\/span>.<\/span>name<\/span>}: ${<\/span>e<\/span>.<\/span>message<\/span>}`<\/span>);<\/span>\n}<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>new<\/span> <\/span>UserF<\/span>(<\/span>\"\u0410\u043d\u044f\"<\/span>).<\/span>name<\/span>);<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434:<\/p>\n
      TypeError: UserF \u043d\u0443\u0436\u043d\u043e \u0432\u044b\u0437\u044b\u0432\u0430\u0442\u044c \u0447\u0435\u0440\u0435\u0437 new\n\u0410\u043d\u044f\n<\/code><\/pre>\n
      \u041a\u043b\u0430\u0441\u0441\u044b: extends, super, \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u044b\u0435 \u0438 \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0435 \u043f\u043e\u043b\u044f<\/h2>\n
      \u041a\u043b\u0430\u0441\u0441 \u0447\u0430\u0441\u0442\u043e \u043d\u0430\u0437\u044b\u0432\u0430\u044e\u0442 \u0441\u0438\u043d\u0442\u0430\u043a\u0441\u0438\u0447\u0435\u0441\u043a\u0438\u043c \u0441\u0430\u0445\u0430\u0440\u043e\u043c \u043d\u0430\u0434 \u0444\u0443\u043d\u043a\u0446\u0438\u0435\u0439-\u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u043e\u043c. \u042d\u0442\u043e \u0443\u043f\u0440\u043e\u0449\u0435\u043d\u0438\u0435: \u0446\u0435\u043f\u043e\u0447\u043a\u0430 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u0432 \u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0442\u0435\u043b\u044c\u043d\u043e \u0442\u0430 \u0436\u0435, \u043d\u043e \u0443 \u043a\u043b\u0430\u0441\u0441\u043e\u0432 \u0435\u0441\u0442\u044c \u043e\u0442\u043b\u0438\u0447\u0438\u044f, \u043a\u043e\u0442\u043e\u0440\u044b\u0445 \u043d\u0435\u0442 \u0443 \u043e\u0431\u044b\u0447\u043d\u043e\u0439 \u0444\u0443\u043d\u043a\u0446\u0438\u0438. \u0422\u0435\u043b\u043e \u043a\u043b\u0430\u0441\u0441\u0430 \u0432\u0441\u0435\u0433\u0434\u0430 \u0432 \u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0440\u0435\u0436\u0438\u043c\u0435, \u043c\u0435\u0442\u043e\u0434\u044b \u043d\u0435\u043f\u0435\u0440\u0435\u0447\u0438\u0441\u043b\u044f\u0435\u043c\u044b\u0435 (\u043d\u0435 \u0432\u0438\u0434\u043d\u044b \u0432 for...in<\/code>), \u043a\u043b\u0430\u0441\u0441 \u043d\u0435\u043b\u044c\u0437\u044f \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u0431\u0435\u0437 new<\/code>, \u0434\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f \u043a \u043d\u0435\u043c\u0443 \u043d\u0435\u043b\u044c\u0437\u044f \u043e\u0431\u0440\u0430\u0442\u0438\u0442\u044c\u0441\u044f, \u0430 \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u044b\u0435 \u043f\u043e\u043b\u044f #<\/code> \u0434\u043e\u0441\u0442\u0443\u043f\u043d\u044b \u0442\u043e\u043b\u044c\u043a\u043e \u0441\u0438\u043d\u0442\u0430\u043a\u0441\u0438\u0441\u043e\u043c \u043a\u043b\u0430\u0441\u0441\u0430.<\/p>\n
      class<\/span> <\/span>Account<\/span> {<\/span>\n  <\/span>#balance<\/span> <\/span>=<\/span> <\/span>0<\/span>;                    <\/span>\/\/ \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0435 \u043f\u043e\u043b\u0435, \u0441\u0443\u043c\u043c\u044b - \u0432 \u043a\u043e\u043f\u0435\u0439\u043a\u0430\u0445<\/span>\n  <\/span>static<\/span> <\/span>count<\/span> <\/span>=<\/span> <\/span>0<\/span>;                <\/span>\/\/ \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u043a\u043b\u0430\u0441\u0441\u0430<\/span>\n\n  <\/span>constructor<\/span>(<\/span>owner<\/span>) {<\/span>\n    <\/span>this<\/span>.<\/span>owner<\/span> <\/span>=<\/span> <\/span>owner<\/span>;<\/span>\n    <\/span>Account<\/span>.<\/span>count<\/span>++<\/span>;<\/span>\n  }<\/span>\n  <\/span>deposit<\/span>(<\/span>kopecks<\/span>) {<\/span>\n    <\/span>if<\/span> (<\/span>!<\/span>Number<\/span>.<\/span>isSafeInteger<\/span>(<\/span>kopecks<\/span>) <\/span>||<\/span> <\/span>kopecks<\/span> <\/span><=<\/span> <\/span>0<\/span>) {<\/span>\n      <\/span>throw<\/span> <\/span>new<\/span> <\/span>RangeError<\/span>(<\/span>`\u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: ${<\/span>kopecks<\/span>}`<\/span>);<\/span>\n    }<\/span>\n    <\/span>this<\/span>.<\/span>#balance<\/span> <\/span>+=<\/span> <\/span>kopecks<\/span>;<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>;<\/span>\n  }<\/span>\n  <\/span>get<\/span> <\/span>balance<\/span>() {                  <\/span>\/\/ \u0442\u043e\u043b\u044c\u043a\u043e \u0447\u0442\u0435\u043d\u0438\u0435 \u0441\u043d\u0430\u0440\u0443\u0436\u0438<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>.<\/span>#balance<\/span>;<\/span>\n  }<\/span>\n}<\/span>\n\nclass<\/span> <\/span>SavingsAccount<\/span> <\/span>extends<\/span> <\/span>Account<\/span> {<\/span>\n  <\/span>constructor<\/span>(<\/span>owner<\/span>, <\/span>rate<\/span>) {<\/span>\n    <\/span>super<\/span>(<\/span>owner<\/span>);                  <\/span>\/\/ \u0434\u043e super() this \u043d\u0435\u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d<\/span>\n    <\/span>this<\/span>.<\/span>rate<\/span> <\/span>=<\/span> <\/span>rate<\/span>;<\/span>\n  }<\/span>\n  <\/span>addInterest<\/span>() {<\/span>\n    <\/span>const<\/span> <\/span>interest<\/span> <\/span>=<\/span> <\/span>Math<\/span>.<\/span>round<\/span>(<\/span>this<\/span>.<\/span>balance<\/span> <\/span>*<\/span> <\/span>this<\/span>.<\/span>rate<\/span>);<\/span>\n    <\/span>return<\/span> <\/span>interest<\/span> <\/span>><\/span> <\/span>0<\/span> <\/span>?<\/span> <\/span>this<\/span>.<\/span>deposit<\/span>(<\/span>interest<\/span>) <\/span>:<\/span> <\/span>this<\/span>; <\/span>\/\/ 0 \u043a\u043e\u043f\u0435\u0435\u043a - \u043d\u0435 \u043e\u0448\u0438\u0431\u043a\u0430<\/span>\n  }<\/span>\n}<\/span>\n\nconst<\/span> <\/span>acc<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>SavingsAccount<\/span>(<\/span>\"\u0410\u043d\u044f\"<\/span>, <\/span>0.1<\/span>);<\/span>\nacc<\/span>.<\/span>deposit<\/span>(<\/span>100000<\/span>).<\/span>addInterest<\/span>();<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>acc<\/span>.<\/span>balance<\/span>, <\/span>Account<\/span>.<\/span>count<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>keys<\/span>(<\/span>acc<\/span>), <\/span>acc<\/span>[<\/span>\"#balance\"<\/span>]);<\/span>\nfor<\/span> (<\/span>const<\/span> <\/span>bad<\/span> <\/span>of<\/span> [<\/span>-<\/span>5<\/span>, <\/span>0.5<\/span>, <\/span>NaN<\/span>, <\/span>\"100\"<\/span>]) {<\/span>\n  <\/span>try<\/span> {<\/span>\n    <\/span>acc<\/span>.<\/span>deposit<\/span>(<\/span>bad<\/span>);<\/span>\n  } <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n    <\/span>console<\/span>.<\/span>log<\/span>(<\/span>`${<\/span>e<\/span>.<\/span>name<\/span>}: ${<\/span>e<\/span>.<\/span>message<\/span>}`<\/span>);<\/span>\n  }<\/span>\n}<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434:<\/p>\n
      110000 1\n[ 'owner', 'rate' ] undefined\nRangeError: \u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: -5\nRangeError: \u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: 0.5\nRangeError: \u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: NaN\nRangeError: \u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: 100\n<\/code><\/pre>\n
      \u0420\u0430\u0437\u0431\u043e\u0440. \u041f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0435 \u043f\u043e\u043b\u0435 #balance<\/code> \u043d\u0435 \u0432\u0438\u0434\u043d\u043e \u043d\u0438 \u0432 Object.keys<\/code>, \u043d\u0438 \u0447\u0435\u0440\u0435\u0437 acc[\"#balance\"]<\/code>, \u0430 \u043f\u0440\u044f\u043c\u043e\u0435 acc.#balance<\/code> \u0432\u043d\u0435 \u043a\u043b\u0430\u0441\u0441\u0430 — \u0441\u0438\u043d\u0442\u0430\u043a\u0441\u0438\u0447\u0435\u0441\u043a\u0430\u044f \u043e\u0448\u0438\u0431\u043a\u0430 \u0435\u0449\u0435 \u0434\u043e \u0437\u0430\u043f\u0443\u0441\u043a\u0430. \u0413\u0435\u0442\u0442\u0435\u0440 balance<\/code> \u0434\u0430\u0435\u0442 \u0442\u043e\u043b\u044c\u043a\u043e \u0447\u0442\u0435\u043d\u0438\u0435: \u0432 \u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0440\u0435\u0436\u0438\u043c\u0435 (ES-\u043c\u043e\u0434\u0443\u043b\u044c) \u043f\u043e\u043f\u044b\u0442\u043a\u0430 acc.balance = 1<\/code> \u0431\u0440\u043e\u0441\u0430\u0435\u0442 TypeError<\/code>, \u0432 \u043d\u0435\u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0441\u043a\u0440\u0438\u043f\u0442\u0435 \u0437\u0430\u043f\u0438\u0441\u044c \u043c\u043e\u043b\u0447\u0430 \u0438\u0433\u043d\u043e\u0440\u0438\u0440\u0443\u0435\u0442\u0441\u044f. \u0421\u0443\u043c\u043c\u044b \u0445\u0440\u0430\u043d\u044f\u0442\u0441\u044f \u0446\u0435\u043b\u044b\u043c\u0438 \u043a\u043e\u043f\u0435\u0439\u043a\u0430\u043c\u0438, \u0447\u0442\u043e\u0431\u044b \u043d\u0435 \u043b\u043e\u0432\u0438\u0442\u044c \u043e\u0448\u0438\u0431\u043a\u0438 \u043e\u043a\u0440\u0443\u0433\u043b\u0435\u043d\u0438\u044f 0.1 + 0.2<\/code>, \u0430 \u043c\u0435\u0442\u043e\u0434 \u043e\u0442\u043a\u043b\u043e\u043d\u044f\u0435\u0442 \u043d\u0435 \u0442\u043e\u043b\u044c\u043a\u043e \u043e\u0442\u0440\u0438\u0446\u0430\u0442\u0435\u043b\u044c\u043d\u044b\u0435 \u0447\u0438\u0441\u043b\u0430, \u043d\u043e \u0438 \u0434\u0440\u043e\u0431\u0438, NaN<\/code> \u0438 \u0441\u0442\u0440\u043e\u043a\u0443. \u041f\u0440\u043e\u0432\u0435\u0440\u043a\u0430 \u0432 addInterest<\/code> \u043d\u0443\u0436\u043d\u0430 \u0438\u0437-\u0437\u0430 \u0442\u043e\u0433\u043e \u0436\u0435 \u0432\u0430\u043b\u0438\u0434\u0430\u0442\u043e\u0440\u0430: \u043d\u0430 \u043d\u0443\u043b\u0435\u0432\u043e\u043c \u0431\u0430\u043b\u0430\u043d\u0441\u0435 \u0438\u043b\u0438 \u043f\u0440\u0438 \u0441\u0443\u043c\u043c\u0435 \u043c\u0435\u043d\u044c\u0448\u0435 \u043a\u043e\u043f\u0435\u0439\u043a\u0438 \u043f\u0440\u043e\u0446\u0435\u043d\u0442 \u043e\u043a\u0440\u0443\u0433\u043b\u044f\u0435\u0442\u0441\u044f \u0434\u043e 0, \u0438 \u043f\u0440\u044f\u043c\u043e\u0439 \u0432\u044b\u0437\u043e\u0432 deposit(0)<\/code> \u0431\u0440\u043e\u0441\u0438\u043b \u0431\u044b RangeError: \u043d\u0435\u043a\u043e\u0440\u0440\u0435\u043a\u0442\u043d\u0430\u044f \u0441\u0443\u043c\u043c\u0430: 0<\/code> — \u043d\u0430\u0447\u0438\u0441\u043b\u0435\u043d\u0438\u0435 \u00ab\u043d\u0438\u0447\u0435\u0433\u043e\u00bb \u043d\u0435 \u0434\u043e\u043b\u0436\u043d\u043e \u0440\u043e\u043d\u044f\u0442\u044c \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u0443.<\/p>\n
      \u0427\u0430\u0441\u0442\u0430\u044f \u043e\u0448\u0438\u0431\u043a\u0430 \u0432 \u043d\u0430\u0441\u043b\u0435\u0434\u043d\u0438\u043a\u0435 — \u043e\u0431\u0440\u0430\u0442\u0438\u0442\u044c\u0441\u044f \u043a this<\/code> \u0434\u043e super()<\/code>:<\/p>\n
      class<\/span> <\/span>Base<\/span> {}<\/span>\nclass<\/span> <\/span>Broken<\/span> <\/span>extends<\/span> <\/span>Base<\/span> {<\/span>\n  <\/span>constructor<\/span>() {<\/span>\n    <\/span>this<\/span>.<\/span>x<\/span> <\/span>=<\/span> <\/span>1<\/span>;                    <\/span>\/\/ \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435 \u043a this \u0434\u043e super()<\/span>\n    <\/span>super<\/span>();<\/span>\n  }<\/span>\n}<\/span>\ntry<\/span> {<\/span>\n  <\/span>new<\/span> <\/span>Broken<\/span>();<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>`${<\/span>e<\/span>.<\/span>name<\/span>}: ${<\/span>e<\/span>.<\/span>message<\/span>}`<\/span>);<\/span>\n}<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434 (\u0442\u0435\u043a\u0441\u0442 \u0441\u043e\u043e\u0431\u0449\u0435\u043d\u0438\u044f — \u0434\u0432\u0438\u0436\u043a\u0430 V8 \u0432 Node.js 24, \u0432 \u0434\u0440\u0443\u0433\u0438\u0445 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0430\u0445 \u0444\u043e\u0440\u043c\u0443\u043b\u0438\u0440\u043e\u0432\u043a\u0430 \u0438\u043d\u0430\u044f):<\/p>\n
      ReferenceError: Must call super constructor in derived class before accessing 'this' or returning from derived constructor\n<\/code><\/pre>\n
      \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 — \u043f\u0435\u0440\u0432\u043e\u0439 \u0441\u0442\u0440\u043e\u043a\u043e\u0439 \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u0430 \u0432\u044b\u0437\u0432\u0430\u0442\u044c super(...)<\/code>, \u043a\u0430\u043a \u0432 SavingsAccount<\/code> \u0432\u044b\u0448\u0435. \u0415\u0441\u043b\u0438 \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440 \u043d\u0430\u0441\u043b\u0435\u0434\u043d\u0438\u043a\u0430 \u043d\u0435 \u043d\u0443\u0436\u0435\u043d, \u0435\u0433\u043e \u043c\u043e\u0436\u043d\u043e \u043d\u0435 \u043f\u0438\u0441\u0430\u0442\u044c: \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e \u043e\u043d \u043f\u0435\u0440\u0435\u0434\u0430\u0441\u0442 \u0432\u0441\u0435 \u0430\u0440\u0433\u0443\u043c\u0435\u043d\u0442\u044b \u0432 super<\/code>.<\/p>\n
      \u041a\u0430\u043a extends<\/code> \u0432\u044b\u0433\u043b\u044f\u0434\u0438\u0442 \u0431\u0435\u0437 \u043a\u043b\u0430\u0441\u0441\u043e\u0432<\/h2>\n
      \u0427\u0442\u043e\u0431\u044b \u043f\u043e\u043d\u0438\u043c\u0430\u0442\u044c \u0441\u0442\u0430\u0440\u044b\u0439 \u043a\u043e\u0434 \u0438 \u0442\u043e, \u0447\u0442\u043e \u0434\u0435\u043b\u0430\u0435\u0442 extends<\/code>, \u043f\u043e\u043b\u0435\u0437\u043d\u043e \u043e\u0434\u0438\u043d \u0440\u0430\u0437 \u0441\u043e\u0431\u0440\u0430\u0442\u044c \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0435 \u0432\u0440\u0443\u0447\u043d\u0443\u044e:<\/p>\n
      function<\/span> <\/span>Animal<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>this<\/span>.<\/span>name<\/span> <\/span>=<\/span> <\/span>name<\/span>;<\/span>\n}<\/span>\nAnimal<\/span>.<\/span>prototype<\/span>.<\/span>speak<\/span> <\/span>=<\/span> <\/span>function<\/span> () {<\/span>\n  <\/span>return<\/span> <\/span>`${<\/span>this<\/span>.<\/span>name<\/span>} \u0438\u0437\u0434\u0430\u0435\u0442 \u0437\u0432\u0443\u043a`<\/span>;<\/span>\n};<\/span>\n\nfunction<\/span> <\/span>Dog<\/span>(<\/span>name<\/span>) {<\/span>\n  <\/span>Animal<\/span>.<\/span>call<\/span>(<\/span>this<\/span>, <\/span>name<\/span>);                         <\/span>\/\/ \u0430\u043d\u0430\u043b\u043e\u0433 super(name)<\/span>\n}<\/span>\nDog<\/span>.<\/span>prototype<\/span> <\/span>=<\/span> <\/span>Object<\/span>.<\/span>create<\/span>(<\/span>Animal<\/span>.<\/span>prototype<\/span>);   <\/span>\/\/ \u0441\u0432\u044f\u0437\u044b\u0432\u0430\u0435\u043c \u0446\u0435\u043f\u043e\u0447\u043a\u0443<\/span>\nDog<\/span>.<\/span>prototype<\/span>.<\/span>constructor<\/span> <\/span>=<\/span> <\/span>Dog<\/span>;                   <\/span>\/\/ \u0432\u043e\u0441\u0441\u0442\u0430\u043d\u0430\u0432\u043b\u0438\u0432\u0430\u0435\u043c \u0441\u0441\u044b\u043b\u043a\u0443<\/span>\nDog<\/span>.<\/span>prototype<\/span>.<\/span>speak<\/span> <\/span>=<\/span> <\/span>function<\/span> () {<\/span>\n  <\/span>return<\/span> <\/span>`${<\/span>Animal<\/span>.<\/span>prototype<\/span>.<\/span>speak<\/span>.<\/span>call<\/span>(<\/span>this<\/span>)<\/span>} \u0438 \u043b\u0430\u0435\u0442`<\/span>;<\/span>\n};<\/span>\n\nconst<\/span> <\/span>rex<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Dog<\/span>(<\/span>\"\u0420\u0435\u043a\u0441\"<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>rex<\/span>.<\/span>speak<\/span>(), <\/span>rex<\/span> <\/span>instanceof<\/span> <\/span>Animal<\/span>, <\/span>rex<\/span>.<\/span>constructor<\/span>.<\/span>name<\/span>);<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434: \u0420\u0435\u043a\u0441 \u0438\u0437\u0434\u0430\u0435\u0442 \u0437\u0432\u0443\u043a \u0438 \u043b\u0430\u0435\u0442 true Dog<\/code>. \u0415\u0441\u043b\u0438 \u043f\u0440\u043e\u043f\u0443\u0441\u0442\u0438\u0442\u044c \u0441\u0442\u0440\u043e\u043a\u0443 \u0441 constructor<\/code>, rex.constructor.name<\/code> \u0432\u0435\u0440\u043d\u0435\u0442 Animal<\/code> — \u0441\u0441\u044b\u043b\u043a\u0430 \u0443\u043d\u0430\u0441\u043b\u0435\u0434\u0443\u0435\u0442\u0441\u044f \u043e\u0442 Animal.prototype<\/code>. \u0412 \u043d\u043e\u0432\u043e\u043c \u043a\u043e\u0434\u0435 \u044d\u0442\u043e\u0442 \u0448\u0430\u0431\u043b\u043e\u043d \u0437\u0430\u043c\u0435\u043d\u044f\u0435\u0442 class Dog extends Animal<\/code>.<\/p>\n
      \u0422\u0438\u043f\u0438\u0447\u043d\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438<\/h2>\n
      \u041f\u043e\u0442\u0435\u0440\u044f this<\/code> \u043f\u0440\u0438 \u043f\u0435\u0440\u0435\u0434\u0430\u0447\u0435 \u043c\u0435\u0442\u043e\u0434\u0430.<\/strong> \u041c\u0435\u0442\u043e\u0434, \u0441\u043e\u0445\u0440\u0430\u043d\u0435\u043d\u043d\u044b\u0439 \u0432 \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u0443\u044e \u0438\u043b\u0438 \u043f\u0435\u0440\u0435\u0434\u0430\u043d\u043d\u044b\u0439 \u043a\u0430\u043a \u043a\u043e\u043b\u0431\u044d\u043a (setTimeout(obj.method)<\/code>), \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0431\u0435\u0437 \u043e\u0431\u044a\u0435\u043a\u0442\u0430:<\/p>\n
      class<\/span> <\/span>Counter<\/span> {<\/span>\n  <\/span>count<\/span> <\/span>=<\/span> <\/span>0<\/span>;<\/span>\n  <\/span>inc<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>++<\/span>this<\/span>.<\/span>count<\/span>;<\/span>\n  }<\/span>\n}<\/span>\nconst<\/span> <\/span>c<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Counter<\/span>();<\/span>\nconst<\/span> <\/span>inc<\/span> <\/span>=<\/span> <\/span>c<\/span>.<\/span>inc<\/span>;                 <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u043e\u0442\u043e\u0440\u0432\u0430\u043d \u043e\u0442 \u043e\u0431\u044a\u0435\u043a\u0442\u0430<\/span>\ntry<\/span> {<\/span>\n  <\/span>inc<\/span>();<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>`${<\/span>e<\/span>.<\/span>name<\/span>}: ${<\/span>e<\/span>.<\/span>message<\/span>}`<\/span>);<\/span>\n}<\/span>\nconst<\/span> <\/span>bound<\/span> <\/span>=<\/span> <\/span>c<\/span>.<\/span>inc<\/span>.<\/span>bind<\/span>(<\/span>c<\/span>);       <\/span>\/\/ \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 1: bind<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>bound<\/span>(), <\/span>bound<\/span>());<\/span>\n\nclass<\/span> <\/span>Counter2<\/span> {<\/span>\n  <\/span>count<\/span> <\/span>=<\/span> <\/span>0<\/span>;<\/span>\n  <\/span>inc<\/span> <\/span>=<\/span> () => <\/span>++<\/span>this<\/span>.<\/span>count<\/span>;        <\/span>\/\/ \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 2: \u0441\u0442\u0440\u0435\u043b\u043a\u0430 \u0432 \u043f\u043e\u043b\u0435 \u043a\u043b\u0430\u0441\u0441\u0430<\/span>\n}<\/span>\nconst<\/span> <\/span>c2<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Counter2<\/span>();<\/span>\nconst<\/span> <\/span>inc2<\/span> <\/span>=<\/span> <\/span>c2<\/span>.<\/span>inc<\/span>;<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>inc2<\/span>(), <\/span>Object<\/span>.<\/span>hasOwn<\/span>(<\/span>c2<\/span>, <\/span>\"inc\"<\/span>));<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434:<\/p>\n
      TypeError: Cannot read properties of undefined (reading 'count')\n1 2\n1 true\n<\/code><\/pre>\n
      \u0421\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u0432 \u043f\u043e\u043b\u0435 \u0443\u0434\u043e\u0431\u043d\u0430 \u0434\u043b\u044f \u043e\u0431\u0440\u0430\u0431\u043e\u0442\u0447\u0438\u043a\u043e\u0432 \u0441\u043e\u0431\u044b\u0442\u0438\u0439, \u043d\u043e \u043e\u043d\u0430 \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e\u0435 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u043a\u0430\u0436\u0434\u043e\u0433\u043e \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u0430, \u0430 \u043d\u0435 \u043c\u0435\u0442\u043e\u0434 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0430. \u041e\u0442\u0441\u044e\u0434\u0430 \u043b\u043e\u0432\u0443\u0448\u043a\u0430 \u043f\u0440\u0438 \u043d\u0430\u0441\u043b\u0435\u0434\u043e\u0432\u0430\u043d\u0438\u0438: \u0435\u0441\u043b\u0438 \u043d\u0430\u0441\u043b\u0435\u0434\u043d\u0438\u043a \u043e\u0431\u044a\u044f\u0432\u0438\u0442 \u043e\u0431\u044b\u0447\u043d\u044b\u0439 \u043c\u0435\u0442\u043e\u0434 inc()<\/code>, \u043e\u043d \u043b\u0435\u0436\u0438\u0442 \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435 \u0438 \u043f\u0435\u0440\u0435\u043a\u0440\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u043f\u043e\u043b\u0435\u043c \u0440\u043e\u0434\u0438\u0442\u0435\u043b\u044f — new Child().inc()<\/code> \u0432\u044b\u0437\u043e\u0432\u0435\u0442 \u0440\u043e\u0434\u0438\u0442\u0435\u043b\u044c\u0441\u043a\u0443\u044e \u0441\u0442\u0440\u0435\u043b\u043a\u0443. \u0410 super.inc()<\/code> \u0438\u0437 \u043d\u0430\u0441\u043b\u0435\u0434\u043d\u0438\u043a\u0430 \u043d\u0435 \u043d\u0430\u0439\u0434\u0435\u0442 \u0435\u0435 \u0432\u043e\u0432\u0441\u0435, \u043f\u043e\u0442\u043e\u043c\u0443 \u0447\u0442\u043e \u0432 Counter2.prototype<\/code> \u043c\u0435\u0442\u043e\u0434\u0430 \u043d\u0435\u0442.<\/p>\n
      \u0418\u0437\u043c\u0435\u043d\u044f\u0435\u043c\u044b\u0435 \u0434\u0430\u043d\u043d\u044b\u0435 \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435.<\/strong> \u041f\u0440\u043e\u0442\u043e\u0442\u0438\u043f \u043e\u0431\u0449\u0438\u0439 \u0434\u043b\u044f \u0432\u0441\u0435\u0445 \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u043e\u0432, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 \u043c\u0430\u0441\u0441\u0438\u0432 \u0438\u043b\u0438 \u043e\u0431\u044a\u0435\u043a\u0442 \u0432 \u043d\u0435\u043c \u0442\u043e\u0436\u0435 \u043e\u0431\u0449\u0438\u0439:<\/p>\n
      function<\/span> <\/span>Cart<\/span>() {}<\/span>\nCart<\/span>.<\/span>prototype<\/span>.<\/span>items<\/span> <\/span>=<\/span> [];         <\/span>\/\/ \u043e\u0448\u0438\u0431\u043a\u0430: \u043e\u0434\u0438\u043d \u043c\u0430\u0441\u0441\u0438\u0432 \u043d\u0430 \u0432\u0441\u0435 \u043a\u043e\u0440\u0437\u0438\u043d\u044b<\/span>\n\nconst<\/span> <\/span>a<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Cart<\/span>();<\/span>\nconst<\/span> <\/span>b<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Cart<\/span>();<\/span>\na<\/span>.<\/span>items<\/span>.<\/span>push<\/span>(<\/span>\"\u043a\u043d\u0438\u0433\u0430\"<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>b<\/span>.<\/span>items<\/span>);<\/span>\n\nfunction<\/span> <\/span>FixedCart<\/span>() {<\/span>\n  <\/span>this<\/span>.<\/span>items<\/span> <\/span>=<\/span> [];                 <\/span>\/\/ \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435: \u0441\u0432\u043e\u0435 \u0441\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 - \u0432 \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u0435<\/span>\n}<\/span>\nconst<\/span> <\/span>x<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>FixedCart<\/span>();<\/span>\nconst<\/span> <\/span>y<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>FixedCart<\/span>();<\/span>\nx<\/span>.<\/span>items<\/span>.<\/span>push<\/span>(<\/span>\"\u043a\u043d\u0438\u0433\u0430\"<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>y<\/span>.<\/span>items<\/span>);<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434: \u0441\u043d\u0430\u0447\u0430\u043b\u0430 [ '\u043a\u043d\u0438\u0433\u0430' ]<\/code> (\u0442\u043e\u0432\u0430\u0440 \u043f\u043e\u044f\u0432\u0438\u043b\u0441\u044f \u0432 \u0447\u0443\u0436\u043e\u0439 \u043a\u043e\u0440\u0437\u0438\u043d\u0435), \u0437\u0430\u0442\u0435\u043c []<\/code>. \u041f\u0440\u0430\u0432\u0438\u043b\u043e: \u0432 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435 — \u043c\u0435\u0442\u043e\u0434\u044b \u0438 \u043a\u043e\u043d\u0441\u0442\u0430\u043d\u0442\u044b, \u0438\u0437\u043c\u0435\u043d\u044f\u0435\u043c\u043e\u0435 \u0441\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 — \u0432 \u043a\u043e\u043d\u0441\u0442\u0440\u0443\u043a\u0442\u043e\u0440\u0435 \u0438\u043b\u0438 \u043f\u043e\u043b\u044f\u0445 \u043a\u043b\u0430\u0441\u0441\u0430.<\/p>\n
      \u0420\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0435 \u0432\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u044b\u0445 \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u043e\u0432.<\/strong> \u0414\u043e\u0431\u0430\u0432\u0438\u0442\u044c \u043c\u0435\u0442\u043e\u0434 \u0432\u0441\u0435\u043c \u043e\u0431\u044a\u0435\u043a\u0442\u0430\u043c \u0447\u0435\u0440\u0435\u0437 Object.prototype<\/code> \u0442\u0435\u0445\u043d\u0438\u0447\u0435\u0441\u043a\u0438 \u043c\u043e\u0436\u043d\u043e, \u043d\u043e \u043e\u043d \u043f\u043e\u044f\u0432\u0438\u0442\u0441\u044f \u0432 \u043a\u0430\u0436\u0434\u043e\u043c for...in<\/code>:<\/p>\n
      Object<\/span>.<\/span>prototype<\/span>.<\/span>sayHello<\/span> <\/span>=<\/span> <\/span>function<\/span> () {<\/span>\n  <\/span>return<\/span> <\/span>\"Hello\"<\/span>;<\/span>\n};<\/span>\nconst<\/span> <\/span>user<\/span> <\/span>=<\/span> { <\/span>name<\/span>:<\/span> <\/span>\"\u0410\u043d\u044f\"<\/span> };<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>user<\/span>.<\/span>sayHello<\/span>());<\/span>\nfor<\/span> (<\/span>const<\/span> <\/span>key<\/span> <\/span>in<\/span> <\/span>user<\/span>) <\/span>console<\/span>.<\/span>log<\/span>(<\/span>\"for...in:\"<\/span>, <\/span>key<\/span>);<\/span>\ndelete<\/span> <\/span>Object<\/span>.<\/span>prototype<\/span>.<\/span>sayHello<\/span>;<\/span><\/code><\/pre>\n
      \u0412\u044b\u0432\u043e\u0434: Hello<\/code>, \u0437\u0430\u0442\u0435\u043c for...in: name<\/code> \u0438 for...in: sayHello<\/code>. \u041a\u0440\u043e\u043c\u0435 \u043b\u0438\u0448\u043d\u0438\u0445 \u043a\u043b\u044e\u0447\u0435\u0439, \u0442\u0430\u043a\u043e\u0435 \u0440\u0430\u0441\u0448\u0438\u0440\u0435\u043d\u0438\u0435 \u043a\u043e\u043d\u0444\u043b\u0438\u043a\u0442\u0443\u0435\u0442 \u0441 \u0431\u0443\u0434\u0443\u0449\u0438\u043c\u0438 \u043c\u0435\u0442\u043e\u0434\u0430\u043c\u0438 \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u0430 \u0438 \u0447\u0443\u0436\u0438\u043c\u0438 \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0430\u043c\u0438. \u0412\u043c\u0435\u0441\u0442\u043e \u044d\u0442\u043e\u0433\u043e \u043f\u0438\u0448\u0438\u0442\u0435 \u043e\u0431\u044b\u0447\u043d\u0443\u044e \u0444\u0443\u043d\u043a\u0446\u0438\u044e \u0438\u043b\u0438 \u0441\u0432\u043e\u0439 \u043a\u043b\u0430\u0441\u0441.<\/p>\n
      \u0412\u044b\u0432\u043e\u0434\u044b<\/h2>\n