{"id":1740,"date":"2026-09-24T09:00:00","date_gmt":"2026-09-24T09:00:00","guid":{"rendered":"https:\/\/otus.ru\/journal\/?p=1740"},"modified":"2026-09-25T15:31:39","modified_gmt":"2026-09-25T15:31:39","slug":"poleznoe-dlya-programmistov-o-javascript-peremennye-metody-funkcii","status":"publish","type":"post","link":"https:\/\/otus.ru\/journal\/poleznoe-dlya-programmistov-o-javascript-peremennye-metody-funkcii\/","title":{"rendered":"\u0427\u0442\u043e \u0442\u0430\u043a\u043e\u0435 \u043c\u0435\u0442\u043e\u0434 \u0432 JavaScript: \u0444\u0443\u043d\u043a\u0446\u0438\u0438, \u043c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u0435\u043a\u0442\u0430, this \u0438 \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0435"},"content":{"rendered":"

\u041c\u0435\u0442\u043e\u0434 \u0432 JavaScript<\/strong> — \u044d\u0442\u043e \u0444\u0443\u043d\u043a\u0446\u0438\u044f, \u043a\u043e\u0442\u043e\u0440\u0430\u044f \u0445\u0440\u0430\u043d\u0438\u0442\u0441\u044f \u0432 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u0435 \u043e\u0431\u044a\u0435\u043a\u0442\u0430 \u0438 \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0447\u0435\u0440\u0435\u0437 \u0442\u043e\u0447\u043a\u0443: user.greet()<\/code>, \"otus\".toUpperCase()<\/code>, Math.max(3, 7)<\/code>. \u041e\u0442 \u043e\u0431\u044b\u0447\u043d\u043e\u0439 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u043c\u0435\u0442\u043e\u0434 \u043e\u0442\u043b\u0438\u0447\u0430\u0435\u0442\u0441\u044f \u043d\u0435 \u0441\u0438\u043d\u0442\u0430\u043a\u0441\u0438\u0441\u043e\u043c \u0442\u0435\u043b\u0430, \u0430 \u0441\u043f\u043e\u0441\u043e\u0431\u043e\u043c \u0432\u044b\u0437\u043e\u0432\u0430: \u043f\u0440\u0438 \u0432\u044b\u0437\u043e\u0432\u0435 \u0447\u0435\u0440\u0435\u0437 \u0442\u043e\u0447\u043a\u0443 \u0432\u043d\u0443\u0442\u0440\u0438 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u0434\u043e\u0441\u0442\u0443\u043f\u0435\u043d this<\/code> — \u043e\u0431\u044a\u0435\u043a\u0442, \u0443 \u043a\u043e\u0442\u043e\u0440\u043e\u0433\u043e \u0435\u0435 \u0432\u044b\u0437\u0432\u0430\u043b\u0438.<\/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: \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u0430\u044f, \u0444\u0443\u043d\u043a\u0446\u0438\u044f, \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e, \u043c\u0435\u0442\u043e\u0434<\/a><\/li>\n
  2. \u041c\u0438\u043d\u0438\u043c\u0430\u043b\u044c\u043d\u044b\u0439 \u043f\u0440\u0438\u043c\u0435\u0440: \u043e\u0431\u044a\u0435\u043a\u0442 \u0441 \u043c\u0435\u0442\u043e\u0434\u043e\u043c<\/a><\/li>\n
  3. \u041f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0435: let, const \u0438 var<\/a><\/li>\n
  4. \u0422\u0440\u0438 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u043e\u0431\u044a\u044f\u0432\u0438\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u044e<\/a><\/li>\n
  5. \u041c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u0435\u043a\u0442\u0430: \u0432\u044b\u0437\u043e\u0432, \u0441\u0441\u044b\u043b\u043a\u0430 \u0438 \u0434\u043e\u0431\u0430\u0432\u043b\u0435\u043d\u0438\u0435<\/a><\/li>\n
  6. \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 this: \u043f\u0440\u0430\u0432\u0438\u043b\u043e \u043f\u043e \u0441\u043f\u043e\u0441\u043e\u0431\u0443 \u0432\u044b\u0437\u043e\u0432\u0430<\/a><\/li>\n
  7. \u041c\u0435\u0442\u043e\u0434\u044b \u043a\u043b\u0430\u0441\u0441\u0430, \u0433\u0435\u0442\u0442\u0435\u0440\u044b \u0438 \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0435 \u043c\u0435\u0442\u043e\u0434\u044b<\/a><\/li>\n
  8. \u0412\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b, \u043a\u043e\u0442\u043e\u0440\u044b\u0435 \u043d\u0443\u0436\u043d\u044b \u0441 \u043f\u0435\u0440\u0432\u043e\u0433\u043e \u0434\u043d\u044f<\/a><\/li>\n
  9. \u0415\u0441\u043b\u0438 \u043d\u0435 \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c: \u0441\u0438\u043c\u043f\u0442\u043e\u043c -> \u043f\u0440\u0438\u0447\u0438\u043d\u0430<\/a><\/li>\n
  10. \u0412\u044b\u0432\u043e\u0434\u044b<\/a><\/li>\n
  11. \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
  12. FAQ<\/a><\/li>\n<\/ol>\n<\/div>\n

    \u041d\u0438\u0436\u0435 \u0440\u0430\u0437\u0431\u0435\u0440\u0443, \u043a\u0430\u043a \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u0438 (\u0432\u043a\u043b\u044e\u0447\u0430\u044f \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u044b\u0435), \u043a\u0430\u043a \u0443\u0441\u0442\u0440\u043e\u0435\u043d\u044b \u043c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u0432 \u0438 \u043a\u043b\u0430\u0441\u0441\u043e\u0432, \u043f\u043e \u043a\u0430\u043a\u043e\u043c\u0443 \u043f\u0440\u0430\u0432\u0438\u043b\u0443 \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u044f\u0435\u0442\u0441\u044f this<\/code> \u0438 \u0433\u0434\u0435 \u043f\u0440\u0438 \u044d\u0442\u043e\u043c \u043d\u0443\u0436\u043d\u044b let<\/code> \u0438 const<\/code>. \u0412\u0441\u0435 \u043f\u0440\u0438\u043c\u0435\u0440\u044b \u043f\u0440\u043e\u0432\u0435\u0440\u0435\u043d\u044b \u0432 Node.js 24 LTS (\u0432\u044b\u0432\u043e\u0434 \u0441\u043e\u0432\u043f\u0430\u043b \u0432 Node.js 22 \u0438 26).<\/p>\n

    \u041c\u0438\u043d\u0438-\u0441\u043b\u043e\u0432\u0430\u0440\u044c: \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u0430\u044f, \u0444\u0443\u043d\u043a\u0446\u0438\u044f, \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e, \u043c\u0435\u0442\u043e\u0434<\/h2>\n\n\n\n\n\n\n\n\n
    \u0422\u0435\u0440\u043c\u0438\u043d<\/th>\n\u0427\u0442\u043e \u044d\u0442\u043e<\/th>\n\u041f\u0440\u0438\u043c\u0435\u0440<\/th>\n<\/tr>\n<\/thead>\n
    \u041f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u0430\u044f<\/td>\n\u0418\u043c\u044f, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u043e\u0435 \u0441\u043e \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435\u043c<\/td>\nlet count = 0<\/code><\/td>\n<\/tr>\n
    \u0424\u0443\u043d\u043a\u0446\u0438\u044f<\/td>\n\u0417\u043d\u0430\u0447\u0435\u043d\u0438\u0435, \u043a\u043e\u0442\u043e\u0440\u043e\u0435 \u043c\u043e\u0436\u043d\u043e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u0441\u043e \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438<\/td>\nfunction sum(a, b) {...}<\/code><\/td>\n<\/tr>\n
    \u0421\u0432\u043e\u0439\u0441\u0442\u0432\u043e<\/td>\n\u041f\u0430\u0440\u0430 \u00ab\u043a\u043b\u044e\u0447 — \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435\u00bb \u0432\u043d\u0443\u0442\u0440\u0438 \u043e\u0431\u044a\u0435\u043a\u0442\u0430<\/td>\nuser.name<\/code><\/td>\n<\/tr>\n
    \u041c\u0435\u0442\u043e\u0434<\/td>\n\u0421\u0432\u043e\u0439\u0441\u0442\u0432\u043e, \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u043a\u043e\u0442\u043e\u0440\u043e\u0433\u043e — \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/td>\nuser.greet()<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

    \u0413\u043b\u0430\u0432\u043d\u043e\u0435: \u043c\u0435\u0442\u043e\u0434 — \u0447\u0430\u0441\u0442\u043d\u044b\u0439 \u0441\u043b\u0443\u0447\u0430\u0439 \u0444\u0443\u043d\u043a\u0446\u0438\u0438. \u041b\u044e\u0431\u0443\u044e \u0444\u0443\u043d\u043a\u0446\u0438\u044e \u043c\u043e\u0436\u043d\u043e \u043f\u043e\u043b\u043e\u0436\u0438\u0442\u044c \u0432 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u043e\u0431\u044a\u0435\u043a\u0442\u0430, \u0438 \u043e\u043d\u0430 \u0441\u0442\u0430\u043d\u0435\u0442 \u043c\u0435\u0442\u043e\u0434\u043e\u043c \u044d\u0442\u043e\u0433\u043e \u043e\u0431\u044a\u0435\u043a\u0442\u0430.<\/p>\n

    \u041c\u0438\u043d\u0438\u043c\u0430\u043b\u044c\u043d\u044b\u0439 \u043f\u0440\u0438\u043c\u0435\u0440: \u043e\u0431\u044a\u0435\u043a\u0442 \u0441 \u043c\u0435\u0442\u043e\u0434\u043e\u043c<\/h2>\n
    const<\/span> <\/span>user<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>name<\/span>:<\/span> <\/span>\"\u0410\u043d\u043d\u0430\"<\/span>,<\/span>\n  <\/span>city<\/span>:<\/span> <\/span>\"\u041a\u0430\u0437\u0430\u043d\u044c\"<\/span>,<\/span>\n  <\/span>greet<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>`\u041f\u0440\u0438\u0432\u0435\u0442, \u044f ${<\/span>this<\/span>.<\/span>name<\/span>}, \u0433\u043e\u0440\u043e\u0434: ${<\/span>this<\/span>.<\/span>city<\/span>}`<\/span>;<\/span>\n  },<\/span>\n};<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>user<\/span>.<\/span>greet<\/span>());          <\/span>\/\/ \u0432\u044b\u0437\u043e\u0432 \u043c\u0435\u0442\u043e\u0434\u0430<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>typeof<\/span> <\/span>user<\/span>.<\/span>greet<\/span>);     <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 - \u044d\u0442\u043e \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>\"otus\"<\/span>.<\/span>toUpperCase<\/span>());  <\/span>\/\/ \u0432\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u044b\u0439 \u043c\u0435\u0442\u043e\u0434 \u0441\u0442\u0440\u043e\u043a\u0438<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Math<\/span>.<\/span>max<\/span>(<\/span>3<\/span>, <\/span>7<\/span>, <\/span>2<\/span>));     <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u0432\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u043e\u0433\u043e \u043e\u0431\u044a\u0435\u043a\u0442\u0430 Math<\/span><\/code><\/pre>\n
    \u0412 \u043a\u043e\u043d\u0441\u043e\u043b\u0438 \u043f\u043e\u044f\u0432\u0438\u0442\u0441\u044f:<\/p>\n
    \u041f\u0440\u0438\u0432\u0435\u0442, \u044f \u0410\u043d\u043d\u0430, \u0433\u043e\u0440\u043e\u0434: \u041a\u0430\u0437\u0430\u043d\u044c\nfunction\nOTUS\n7\n<\/code><\/pre>\n
    \u0420\u0430\u0437\u0431\u043e\u0440 \u043f\u043e \u0441\u0442\u0440\u043e\u043a\u0430\u043c:
    \n— greet() {...}<\/code> — \u043a\u0440\u0430\u0442\u043a\u0430\u044f \u0437\u0430\u043f\u0438\u0441\u044c \u043c\u0435\u0442\u043e\u0434\u0430 (\u0441 ES2015), \u0442\u043e \u0436\u0435 \u0441\u0430\u043c\u043e\u0435, \u0447\u0442\u043e greet: function () {...}<\/code>;
    \n— this.name<\/code> \u0432\u043d\u0443\u0442\u0440\u0438 \u043c\u0435\u0442\u043e\u0434\u0430 \u0447\u0438\u0442\u0430\u0435\u0442 \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e \u0442\u043e\u0433\u043e \u043e\u0431\u044a\u0435\u043a\u0442\u0430, \u0443 \u043a\u043e\u0442\u043e\u0440\u043e\u0433\u043e \u0432\u044b\u0437\u0432\u0430\u043b\u0438 greet<\/code>, — \u0437\u0434\u0435\u0441\u044c user<\/code>;
    \n— typeof<\/code> \u043f\u043e\u043a\u0430\u0437\u044b\u0432\u0430\u0435\u0442, \u0447\u0442\u043e \u043c\u0435\u0442\u043e\u0434 — \u043e\u0431\u044b\u0447\u043d\u043e\u0435 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u0442\u0438\u043f\u0430 function<\/code>;
    \n— \u0443 \u0441\u0442\u0440\u043e\u043a, \u0447\u0438\u0441\u0435\u043b \u0438 \u0432\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u044b\u0445 \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u0432 (Math<\/code>, Date<\/code>, JSON<\/code>) \u043c\u0435\u0442\u043e\u0434\u044b \u0443\u0436\u0435 \u0435\u0441\u0442\u044c, \u0438\u0445 \u043d\u0435 \u043d\u0443\u0436\u043d\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u0442\u044c.<\/p>\n
    \u041f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u0435: let, const \u0438 var<\/h2>\n
    \u041c\u0435\u0442\u043e\u0434\u044b \u0438 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u043f\u043e\u0447\u0442\u0438 \u0432\u0441\u0435\u0433\u0434\u0430 \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0441 \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u044b\u043c\u0438, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 \u0441\u043d\u0430\u0447\u0430\u043b\u0430 \u043e \u0442\u043e\u043c, \u043a\u0430\u043a \u0438\u0445 \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u0442\u044c. \u0412 \u0441\u043e\u0432\u0440\u0435\u043c\u0435\u043d\u043d\u043e\u043c \u043a\u043e\u0434\u0435 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044e\u0442 const<\/code> \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e \u0438 let<\/code>, \u043a\u043e\u0433\u0434\u0430 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u043d\u0443\u0436\u043d\u043e \u043f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u043e\u0438\u0442\u044c. var<\/code> \u0432\u0441\u0442\u0440\u0435\u0447\u0430\u0435\u0442\u0441\u044f \u0432 \u0441\u0442\u0430\u0440\u043e\u043c \u043a\u043e\u0434\u0435.<\/p>\n
    const<\/span> <\/span>limit<\/span> <\/span>=<\/span> <\/span>10<\/span>;<\/span>\nlet<\/span> <\/span>count<\/span> <\/span>=<\/span> <\/span>0<\/span>;<\/span>\ncount<\/span> <\/span>=<\/span> <\/span>count<\/span> <\/span>+<\/span> <\/span>1<\/span>;          <\/span>\/\/ let \u043c\u043e\u0436\u043d\u043e \u043f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u043e\u0438\u0442\u044c<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>count<\/span>);<\/span>\n\nconst<\/span> <\/span>settings<\/span> <\/span>=<\/span> { <\/span>theme<\/span>:<\/span> <\/span>\"dark\"<\/span> };<\/span>\nsettings<\/span>.<\/span>theme<\/span> <\/span>=<\/span> <\/span>\"light\"<\/span>;   <\/span>\/\/ \u043c\u0435\u043d\u044f\u0442\u044c \u0441\u043e\u0434\u0435\u0440\u0436\u0438\u043c\u043e\u0435 \u043e\u0431\u044a\u0435\u043a\u0442\u0430 \u043c\u043e\u0436\u043d\u043e<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>settings<\/span>.<\/span>theme<\/span>);<\/span>\n\ntry<\/span> {<\/span>\n  <\/span>limit<\/span> <\/span>=<\/span> <\/span>20<\/span>;               <\/span>\/\/ \u0430 \u043f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u043e\u0438\u0442\u044c const \u043d\u0435\u043b\u044c\u0437\u044f<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>e<\/span>.<\/span>name<\/span> <\/span>+<\/span> <\/span>\": \"<\/span> <\/span>+<\/span> <\/span>e<\/span>.<\/span>message<\/span>);<\/span>\n}<\/span>\n\ntry<\/span> {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>total<\/span>);       <\/span>\/\/ \u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435 \u0434\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f let<\/span>\n  <\/span>let<\/span> <\/span>total<\/span> <\/span>=<\/span> <\/span>5<\/span>;<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>e<\/span>.<\/span>name<\/span> <\/span>+<\/span> <\/span>\": \"<\/span> <\/span>+<\/span> <\/span>e<\/span>.<\/span>message<\/span>);<\/span>\n}<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>old<\/span>);           <\/span>\/\/ var \u043f\u043e\u0434\u043d\u0438\u043c\u0430\u0435\u0442\u0441\u044f \u0441\u043e \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435\u043c undefined<\/span>\nvar<\/span> <\/span>old<\/span> <\/span>=<\/span> <\/span>1<\/span>;<\/span>\n\nif<\/span> (<\/span>true<\/span>) {<\/span>\n  <\/span>var<\/span> <\/span>a<\/span> <\/span>=<\/span> <\/span>\"var \u0432\u0438\u0434\u0435\u043d \u0441\u043d\u0430\u0440\u0443\u0436\u0438 \u0431\u043b\u043e\u043a\u0430\"<\/span>;<\/span>\n  <\/span>let<\/span> <\/span>b<\/span> <\/span>=<\/span> <\/span>\"let \u0432\u0438\u0434\u0435\u043d \u0442\u043e\u043b\u044c\u043a\u043e \u0432 \u0431\u043b\u043e\u043a\u0435\"<\/span>;<\/span>\n}<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>a<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>typeof<\/span> <\/span>b<\/span>);<\/span><\/code><\/pre>\n
    1\nlight\nTypeError: Assignment to constant variable.\nReferenceError: Cannot access 'total' before initialization\nundefined\nvar \u0432\u0438\u0434\u0435\u043d \u0441\u043d\u0430\u0440\u0443\u0436\u0438 \u0431\u043b\u043e\u043a\u0430\nundefined\n<\/code><\/pre>\n\n\n\n\n\n\n\n\n
    <\/th>\nconst<\/code><\/th>\nlet<\/code><\/th>\nvar<\/code><\/th>\n<\/tr>\n<\/thead>\n
    \u041e\u0431\u043b\u0430\u0441\u0442\u044c \u0432\u0438\u0434\u0438\u043c\u043e\u0441\u0442\u0438<\/td>\n\u0431\u043b\u043e\u043a {}<\/code><\/td>\n\u0431\u043b\u043e\u043a {}<\/code><\/td>\n\u0432\u0441\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/td>\n<\/tr>\n
    \u041f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u043e\u0438\u0442\u044c<\/td>\n\u043d\u0435\u043b\u044c\u0437\u044f (TypeError)<\/td>\n\u043c\u043e\u0436\u043d\u043e<\/td>\n\u043c\u043e\u0436\u043d\u043e<\/td>\n<\/tr>\n
    \u041e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435 \u0434\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f<\/td>\nReferenceError<\/td>\nReferenceError<\/td>\nundefined<\/code> \u0431\u0435\u0437 \u043e\u0448\u0438\u0431\u043a\u0438<\/td>\n<\/tr>\n
    \u041f\u043e\u0432\u0442\u043e\u0440\u043d\u043e\u0435 \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u0435 \u0432 \u0442\u043e\u0439 \u0436\u0435 \u043e\u0431\u043b\u0430\u0441\u0442\u0438<\/td>\nSyntaxError<\/td>\nSyntaxError<\/td>\n\u0434\u043e\u043f\u0443\u0441\u043a\u0430\u0435\u0442\u0441\u044f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u0412\u0430\u0436\u043d\u0430\u044f \u0433\u0440\u0430\u043d\u0438\u0446\u0430: const<\/code> \u0437\u0430\u043f\u0440\u0435\u0449\u0430\u0435\u0442 \u043f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u043e\u0438\u0442\u044c \u043f\u0435\u0440\u0435\u043c\u0435\u043d\u043d\u0443\u044e, \u043d\u043e \u043d\u0435 \u0434\u0435\u043b\u0430\u0435\u0442 \u043e\u0431\u044a\u0435\u043a\u0442 \u043d\u0435\u0438\u0437\u043c\u0435\u043d\u044f\u0435\u043c\u044b\u043c. \u0414\u043b\u044f \u044d\u0442\u043e\u0433\u043e \u0435\u0441\u0442\u044c Object.freeze()<\/code>, \u0438 \u0442\u043e \u043e\u043d \u0437\u0430\u043c\u043e\u0440\u0430\u0436\u0438\u0432\u0430\u0435\u0442 \u0442\u043e\u043b\u044c\u043a\u043e \u0432\u0435\u0440\u0445\u043d\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u0431\u044a\u0435\u043a\u0442\u0430.<\/p>\n
    \u0422\u0440\u0438 \u0441\u043f\u043e\u0441\u043e\u0431\u0430 \u043e\u0431\u044a\u044f\u0432\u0438\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u044e<\/h2>\n
    \/\/ 1. \u041e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u0435 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 (function declaration)<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>sum<\/span>(<\/span>2<\/span>, <\/span>3<\/span>));            <\/span>\/\/ \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 \u0434\u043e \u0441\u0442\u0440\u043e\u043a\u0438 \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f<\/span>\n\nfunction<\/span> <\/span>sum<\/span>(<\/span>a<\/span>, <\/span>b<\/span>) {<\/span>\n  <\/span>return<\/span> <\/span>a<\/span> <\/span>+<\/span> <\/span>b<\/span>;<\/span>\n}<\/span>\n\n\/\/ 2. \u0424\u0443\u043d\u043a\u0446\u0438\u043e\u043d\u0430\u043b\u044c\u043d\u043e\u0435 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435<\/span>\nconst<\/span> <\/span>multiply<\/span> <\/span>=<\/span> <\/span>function<\/span> (<\/span>a<\/span>, <\/span>b<\/span>) {<\/span>\n  <\/span>return<\/span> <\/span>a<\/span> <\/span>*<\/span> <\/span>b<\/span>;<\/span>\n};<\/span>\n\n\/\/ 3. \u0421\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/span>\nconst<\/span> <\/span>square<\/span> <\/span>=<\/span> (<\/span>x<\/span>) => <\/span>x<\/span> <\/span>*<\/span> <\/span>x<\/span>;       <\/span>\/\/ \u043a\u043e\u0440\u043e\u0442\u043a\u0430\u044f \u0444\u043e\u0440\u043c\u0430: return \u043d\u0435\u044f\u0432\u043d\u044b\u0439<\/span>\nconst<\/span> <\/span>describe<\/span> <\/span>=<\/span> (<\/span>name<\/span>, <\/span>age<\/span> <\/span>=<\/span> <\/span>18<\/span>) => {<\/span>\n  <\/span>return<\/span> <\/span>`${<\/span>name<\/span>}, ${<\/span>age<\/span>}`<\/span>;        <\/span>\/\/ \u0432 \u0444\u0438\u0433\u0443\u0440\u043d\u044b\u0445 \u0441\u043a\u043e\u0431\u043a\u0430\u0445 return \u043d\u0443\u0436\u0435\u043d \u044f\u0432\u043d\u043e<\/span>\n};<\/span>\n\nfunction<\/span> <\/span>noReturn<\/span>() {<\/span>\n  <\/span>const<\/span> <\/span>x<\/span> <\/span>=<\/span> <\/span>1<\/span>;<\/span>\n}<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>multiply<\/span>(<\/span>4<\/span>, <\/span>5<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>square<\/span>(<\/span>9<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>describe<\/span>(<\/span>\"\u041e\u043b\u0435\u0433\"<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>describe<\/span>(<\/span>\"\u041e\u043b\u0435\u0433\"<\/span>, <\/span>30<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>noReturn<\/span>());<\/span><\/code><\/pre>\n
    5\n20\n81\n\u041e\u043b\u0435\u0433, 18\n\u041e\u043b\u0435\u0433, 30\nundefined\n<\/code><\/pre>\n
    age = 18<\/code> — \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u043f\u0430\u0440\u0430\u043c\u0435\u0442\u0440\u0430 \u043f\u043e \u0443\u043c\u043e\u043b\u0447\u0430\u043d\u0438\u044e, \u043e\u043d\u043e \u043f\u043e\u0434\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442\u0441\u044f, \u0435\u0441\u043b\u0438 \u0430\u0440\u0433\u0443\u043c\u0435\u043d\u0442 \u043d\u0435 \u043f\u0435\u0440\u0435\u0434\u0430\u043d. \u0424\u0443\u043d\u043a\u0446\u0438\u044f \u0431\u0435\u0437 return<\/code> \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u0442 undefined<\/code>.<\/p>\n\n\n\n\n\n\n\n\n\n
    \u0421\u0432\u043e\u0439\u0441\u0442\u0432\u043e<\/th>\n\u041e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u0435 function f(){}<\/code><\/th>\n\u0412\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435 const f = function(){}<\/code><\/th>\n\u0421\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f const f = () => {}<\/code><\/th>\n<\/tr>\n<\/thead>\n
    \u041c\u043e\u0436\u043d\u043e \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u0434\u043e \u0441\u0442\u0440\u043e\u043a\u0438 \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f<\/td>\n\u0434\u0430<\/td>\n\u043d\u0435\u0442<\/td>\n\u043d\u0435\u0442<\/td>\n<\/tr>\n
    \u0421\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u044b\u0439 this<\/code><\/td>\n\u0434\u0430, \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u0432\u044b\u0437\u043e\u0432\u0430<\/td>\n\u0434\u0430, \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u0432\u044b\u0437\u043e\u0432\u0430<\/td>\n\u043d\u0435\u0442, \u0431\u0435\u0440\u0435\u0442\u0441\u044f \u0441\u043d\u0430\u0440\u0443\u0436\u0438<\/td>\n<\/tr>\n
    \u0421\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u044b\u0439 arguments<\/code><\/td>\n\u0434\u0430<\/td>\n\u0434\u0430<\/td>\n\u043d\u0435\u0442<\/td>\n<\/tr>\n
    \u0412\u044b\u0437\u043e\u0432 \u0447\u0435\u0440\u0435\u0437 new<\/code><\/td>\n\u0434\u0430<\/td>\n\u0434\u0430<\/td>\n\u043d\u0435\u0442 (TypeError)<\/td>\n<\/tr>\n
    \u0422\u0438\u043f\u0438\u0447\u043d\u043e\u0435 \u043f\u0440\u0438\u043c\u0435\u043d\u0435\u043d\u0438\u0435<\/td>\n\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u043d\u044b\u0435 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u043c\u043e\u0434\u0443\u043b\u044f<\/td>\n\u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043a\u0430\u043a \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435<\/td>\n\u043a\u043e\u043b\u0431\u044d\u043a\u0438, \u043a\u043e\u0440\u043e\u0442\u043a\u0438\u0435 \u043f\u0440\u0435\u043e\u0431\u0440\u0430\u0437\u043e\u0432\u0430\u043d\u0438\u044f<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u0414\u0432\u0435 \u0447\u0430\u0441\u0442\u044b\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 \u0441\u043e \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u044b\u043c\u0438 \u0438 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u044f\u043c\u0438<\/h3>\n
    \u041d\u0435\u0432\u0435\u0440\u043d\u043e: \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u0444\u0443\u043d\u043a\u0446\u0438\u043e\u043d\u0430\u043b\u044c\u043d\u043e\u0435 \u0432\u044b\u0440\u0430\u0436\u0435\u043d\u0438\u0435 \u0438\u043b\u0438 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0443\u044e \u0444\u0443\u043d\u043a\u0446\u0438\u044e \u0434\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f \u0438 \u0437\u0430\u0431\u044b\u0442\u044c, \u0447\u0442\u043e \u0444\u0438\u0433\u0443\u0440\u043d\u044b\u0435 \u0441\u043a\u043e\u0431\u043a\u0438 \u043e\u0442\u043a\u043b\u044e\u0447\u0430\u044e\u0442 \u043d\u0435\u044f\u0432\u043d\u044b\u0439 return<\/code>.<\/p>\n
    try<\/span> {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>twice<\/span>(<\/span>4<\/span>));<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>e<\/span>.<\/span>name<\/span> <\/span>+<\/span> <\/span>\": \"<\/span> <\/span>+<\/span> <\/span>e<\/span>.<\/span>message<\/span>);<\/span>\n}<\/span>\nconst<\/span> <\/span>twice<\/span> <\/span>=<\/span> (<\/span>x<\/span>) => <\/span>x<\/span> <\/span>*<\/span> <\/span>2<\/span>;<\/span>\n\nconst<\/span> <\/span>bad<\/span> <\/span>=<\/span> (<\/span>x<\/span>) => { <\/span>x<\/span> <\/span>*<\/span> <\/span>2<\/span> };<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>bad<\/span>(<\/span>4<\/span>));<\/span>\nconst<\/span> <\/span>makeUser<\/span> <\/span>=<\/span> (<\/span>name<\/span>) => ({ <\/span>name<\/span> });<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>makeUser<\/span>(<\/span>\"\u0418\u0440\u0430\"<\/span>));<\/span><\/code><\/pre>\n
    ReferenceError: Cannot access 'twice' before initialization\nundefined\n{ name: '\u0418\u0440\u0430' }\n<\/code><\/pre>\n
    \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435: \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u0442\u044c const<\/code>-\u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u0432\u044b\u0448\u0435 \u043c\u0435\u0441\u0442\u0430 \u0432\u044b\u0437\u043e\u0432\u0430; \u0432 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u043e\u0439 \u0441 \u0444\u0438\u0433\u0443\u0440\u043d\u044b\u043c\u0438 \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438 \u043f\u0438\u0441\u0430\u0442\u044c return<\/code> \u044f\u0432\u043d\u043e, \u0430 \u043e\u0431\u044a\u0435\u043a\u0442 \u0432 \u043a\u043e\u0440\u043e\u0442\u043a\u043e\u0439 \u0444\u043e\u0440\u043c\u0435 \u043e\u0431\u043e\u0440\u0430\u0447\u0438\u0432\u0430\u0442\u044c \u0432 \u043a\u0440\u0443\u0433\u043b\u044b\u0435 \u0441\u043a\u043e\u0431\u043a\u0438 ({ name })<\/code>.<\/p>\n
    \u041c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u0435\u043a\u0442\u0430: \u0432\u044b\u0437\u043e\u0432, \u0441\u0441\u044b\u043b\u043a\u0430 \u0438 \u0434\u043e\u0431\u0430\u0432\u043b\u0435\u043d\u0438\u0435<\/h2>\n
    const<\/span> <\/span>person<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>firstName<\/span>:<\/span> <\/span>\"\u0418\u0432\u0430\u043d\"<\/span>,<\/span>\n  <\/span>lastName<\/span>:<\/span> <\/span>\"\u041f\u0435\u0442\u0440\u043e\u0432\"<\/span>,<\/span>\n  <\/span>fullName<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>.<\/span>firstName<\/span> <\/span>+<\/span> <\/span>\" \"<\/span> <\/span>+<\/span> <\/span>this<\/span>.<\/span>lastName<\/span>;<\/span>\n  },<\/span>\n};<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>person<\/span>.<\/span>fullName<\/span>());    <\/span>\/\/ \u0441\u043e \u0441\u043a\u043e\u0431\u043a\u0430\u043c\u0438: \u0432\u044b\u0437\u043e\u0432, \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 - \u0441\u0442\u0440\u043e\u043a\u0430<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>person<\/span>.<\/span>fullName<\/span>);      <\/span>\/\/ \u0431\u0435\u0437 \u0441\u043a\u043e\u0431\u043e\u043a: \u0441\u0430\u043c\u0430 \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/span>\nperson<\/span>.<\/span>initials<\/span> <\/span>=<\/span> <\/span>function<\/span> () {    <\/span>\/\/ \u0434\u043e\u0431\u0430\u0432\u0438\u0442\u044c \u043c\u0435\u0442\u043e\u0434 \u043f\u043e\u0441\u043b\u0435 \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044f<\/span>\n  <\/span>return<\/span> <\/span>this<\/span>.<\/span>firstName<\/span>[<\/span>0<\/span>] <\/span>+<\/span> <\/span>\".\"<\/span> <\/span>+<\/span> <\/span>this<\/span>.<\/span>lastName<\/span>[<\/span>0<\/span>] <\/span>+<\/span> <\/span>\".\"<\/span>;<\/span>\n};<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>person<\/span>.<\/span>initials<\/span>());<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>keys<\/span>(<\/span>person<\/span>));<\/span><\/code><\/pre>\n
    \u0418\u0432\u0430\u043d \u041f\u0435\u0442\u0440\u043e\u0432\n[Function: fullName]\n\u0418.\u041f.\n[ 'firstName', 'lastName', 'fullName', 'initials' ]\n<\/code><\/pre>\n
    \u0421\u043a\u043e\u0431\u043a\u0438 \u0440\u0435\u0448\u0430\u044e\u0442 \u0432\u0441\u0435: person.fullName()<\/code> — \u0432\u044b\u0437\u043e\u0432 \u043c\u0435\u0442\u043e\u0434\u0430, person.fullName<\/code> — \u0441\u0441\u044b\u043b\u043a\u0430 \u043d\u0430 \u0444\u0443\u043d\u043a\u0446\u0438\u044e (\u0442\u0430\u043a \u0435\u0435 \u043f\u0435\u0440\u0435\u0434\u0430\u044e\u0442 \u043a\u0430\u043a \u043a\u043e\u043b\u0431\u044d\u043a). \u0424\u043e\u0440\u043c\u0430\u0442 \u0441\u0442\u0440\u043e\u043a\u0438 [Function: fullName]<\/code> — \u044d\u0442\u043e \u0432\u044b\u0432\u043e\u0434 console.log<\/code> \u0432 Node.js, \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u043d\u0430\u044f \u043a\u043e\u043d\u0441\u043e\u043b\u044c \u043f\u043e\u043a\u0430\u0436\u0435\u0442 \u0444\u0443\u043d\u043a\u0446\u0438\u044e \u0438\u043d\u0430\u0447\u0435.<\/p>\n
    \u041a\u0430\u043a \u0440\u0430\u0431\u043e\u0442\u0430\u0435\u0442 this: \u043f\u0440\u0430\u0432\u0438\u043b\u043e \u043f\u043e \u0441\u043f\u043e\u0441\u043e\u0431\u0443 \u0432\u044b\u0437\u043e\u0432\u0430<\/h2>\n
    this<\/code> \u043e\u043f\u0440\u0435\u0434\u0435\u043b\u044f\u0435\u0442\u0441\u044f \u043d\u0435 \u043c\u0435\u0441\u0442\u043e\u043c, \u0433\u0434\u0435 \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043d\u0430\u043f\u0438\u0441\u0430\u043d\u0430, \u0430 \u0442\u0435\u043c, \u043a\u0430\u043a \u0435\u0435 \u0432\u044b\u0437\u0432\u0430\u043b\u0438. \u0418\u0441\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0435 — \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u044b\u0435 \u0444\u0443\u043d\u043a\u0446\u0438\u0438: \u0443 \u043d\u0438\u0445 \u0441\u0432\u043e\u0435\u0433\u043e this<\/code> \u043d\u0435\u0442, \u043e\u043d\u0438 \u0431\u0435\u0440\u0443\u0442 \u0435\u0433\u043e \u0438\u0437 \u043e\u043a\u0440\u0443\u0436\u0430\u044e\u0449\u0435\u0433\u043e \u043a\u043e\u0434\u0430.<\/p>\n\n\n\n\n\n\n\n\n\n\n
    \u041a\u0430\u043a \u0432\u044b\u0437\u0432\u0430\u043b\u0438<\/th>\n\u0427\u0435\u043c\u0443 \u0440\u0430\u0432\u0435\u043d this<\/code><\/th>\n<\/tr>\n<\/thead>\n
    obj.method()<\/code><\/td>\nobj<\/code><\/td>\n<\/tr>\n
    f()<\/code> \u0431\u0435\u0437 \u043e\u0431\u044a\u0435\u043a\u0442\u0430, \u0441\u0442\u0440\u043e\u0433\u0438\u0439 \u0440\u0435\u0436\u0438\u043c<\/td>\nundefined<\/code><\/td>\n<\/tr>\n
    f()<\/code> \u0431\u0435\u0437 \u043e\u0431\u044a\u0435\u043a\u0442\u0430, \u043d\u0435\u0441\u0442\u0440\u043e\u0433\u0438\u0439 \u0440\u0435\u0436\u0438\u043c<\/td>\n\u0433\u043b\u043e\u0431\u0430\u043b\u044c\u043d\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442 (window<\/code> \u0432 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0435)<\/td>\n<\/tr>\n
    f.call(x)<\/code>, f.apply(x)<\/code>, f.bind(x)()<\/code><\/td>\nx<\/code><\/td>\n<\/tr>\n
    new F()<\/code><\/td>\n\u043d\u043e\u0432\u044b\u0439 \u0441\u043e\u0437\u0434\u0430\u0432\u0430\u0435\u043c\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442<\/td>\n<\/tr>\n
    \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f<\/td>\nthis<\/code> \u043e\u043a\u0440\u0443\u0436\u0430\u044e\u0449\u0435\u0433\u043e \u043a\u043e\u0434\u0430<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u041c\u043e\u0434\u0443\u043b\u0438 ES \u0438 \u0442\u0435\u043b\u0430 \u043a\u043b\u0430\u0441\u0441\u043e\u0432 \u0432\u0441\u0435\u0433\u0434\u0430 \u0440\u0430\u0431\u043e\u0442\u0430\u044e\u0442 \u0432 \u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0440\u0435\u0436\u0438\u043c\u0435; \u0432 \u043e\u0431\u044b\u0447\u043d\u043e\u043c \u0441\u043a\u0440\u0438\u043f\u0442\u0435 \u0435\u0433\u043e \u0432\u043a\u043b\u044e\u0447\u0430\u0435\u0442 \u0441\u0442\u0440\u043e\u043a\u0430 \"use strict\"<\/code>.<\/p>\n
    \u041e\u0448\u0438\u0431\u043a\u0430: \u043c\u0435\u0442\u043e\u0434 \u00ab\u043e\u0442\u043e\u0440\u0432\u0430\u043b\u0438\u00bb \u043e\u0442 \u043e\u0431\u044a\u0435\u043a\u0442\u0430<\/h3>\n
    \"use strict\"<\/span>;<\/span>\n\nconst<\/span> <\/span>user<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>name<\/span>:<\/span> <\/span>\"\u0410\u043d\u043d\u0430\"<\/span>,<\/span>\n  <\/span>greet<\/span>() {<\/span>\n    <\/span>return<\/span> <\/span>\"\u042f \"<\/span> <\/span>+<\/span> <\/span>this<\/span>.<\/span>name<\/span>;<\/span>\n  },<\/span>\n  <\/span>greetArrow<\/span>:<\/span> () => {<\/span>\n    <\/span>return<\/span> <\/span>\"\u042f \"<\/span> <\/span>+<\/span> <\/span>this<\/span>?<\/span>.<\/span>name<\/span>;       <\/span>\/\/ \u0443 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u043e\u0439 \u043d\u0435\u0442 \u0441\u0432\u043e\u0435\u0433\u043e this<\/span>\n  },<\/span>\n};<\/span>\n\nconsole<\/span>.<\/span>log<\/span>(<\/span>user<\/span>.<\/span>greet<\/span>());           <\/span>\/\/ this = user<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>user<\/span>.<\/span>greetArrow<\/span>());      <\/span>\/\/ this \u0432\u0437\u044f\u0442 \u0441\u043d\u0430\u0440\u0443\u0436\u0438 \u043e\u0431\u044a\u0435\u043a\u0442\u0430<\/span>\n\nconst<\/span> <\/span>greet<\/span> <\/span>=<\/span> <\/span>user<\/span>.<\/span>greet<\/span>;            <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u00ab\u043e\u0442\u043e\u0440\u0432\u0430\u043b\u0438\u00bb \u043e\u0442 \u043e\u0431\u044a\u0435\u043a\u0442\u0430<\/span>\ntry<\/span> {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>greet<\/span>());<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>e<\/span>.<\/span>name<\/span> <\/span>+<\/span> <\/span>\": \"<\/span> <\/span>+<\/span> <\/span>e<\/span>.<\/span>message<\/span>);<\/span>\n}<\/span>\n\nconst<\/span> <\/span>bound<\/span> <\/span>=<\/span> <\/span>user<\/span>.<\/span>greet<\/span>.<\/span>bind<\/span>(<\/span>user<\/span>); <\/span>\/\/ \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 1: \u043f\u0440\u0438\u0432\u044f\u0437\u0430\u0442\u044c this<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>bound<\/span>());<\/span>\n\nconst<\/span> <\/span>wrapped<\/span> <\/span>=<\/span> () => <\/span>user<\/span>.<\/span>greet<\/span>();  <\/span>\/\/ \u0438\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u0435 2: \u0432\u044b\u0437\u0432\u0430\u0442\u044c \u0447\u0435\u0440\u0435\u0437 \u0442\u043e\u0447\u043a\u0443<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>wrapped<\/span>());<\/span>\n\nconst<\/span> <\/span>other<\/span> <\/span>=<\/span> { <\/span>name<\/span>:<\/span> <\/span>\"\u041e\u043b\u0435\u0433\"<\/span> };<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>user<\/span>.<\/span>greet<\/span>.<\/span>call<\/span>(<\/span>other<\/span>)); <\/span>\/\/ this \u0437\u0430\u0434\u0430\u043d \u044f\u0432\u043d\u043e<\/span><\/code><\/pre>\n
    \u042f \u0410\u043d\u043d\u0430\n\u042f undefined\nTypeError: Cannot read properties of undefined (reading 'name')\n\u042f \u0410\u043d\u043d\u0430\n\u042f \u0410\u043d\u043d\u0430\n\u042f \u041e\u043b\u0435\u0433\n<\/code><\/pre>\n
    \u0427\u0442\u043e \u043f\u0440\u043e\u0438\u0437\u043e\u0448\u043b\u043e. greet()<\/code> \u0431\u0435\u0437 \u0442\u043e\u0447\u043a\u0438 \u043f\u043e\u043b\u0443\u0447\u0438\u043b this = undefined<\/code>, \u0438 \u0447\u0442\u0435\u043d\u0438\u0435 .name<\/code> \u0443\u043f\u0430\u043b\u043e. \u0422\u0430 \u0436\u0435 \u043f\u043e\u0442\u0435\u0440\u044f this<\/code> \u043f\u0440\u043e\u0438\u0441\u0445\u043e\u0434\u0438\u0442, \u043a\u043e\u0433\u0434\u0430 \u043c\u0435\u0442\u043e\u0434 \u043f\u0435\u0440\u0435\u0434\u0430\u044e\u0442 \u043a\u043e\u043b\u0431\u044d\u043a\u043e\u043c, \u043d\u043e \u043f\u0430\u0434\u0435\u043d\u0438\u044f \u043c\u043e\u0436\u0435\u0442 \u0438 \u043d\u0435 \u0431\u044b\u0442\u044c: \u0432 setTimeout(user.greet, 100)<\/code> this<\/code> \u0441\u0442\u0430\u043d\u0435\u0442 \u043e\u0431\u044a\u0435\u043a\u0442\u043e\u043c Timeout<\/code> \u0432 Node.js \u0438\u043b\u0438 window<\/code> \u0432 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u0435, \u0430 \u0432 button.addEventListener(\"click\", user.greet)<\/code> — \u044d\u043b\u0435\u043c\u0435\u043d\u0442\u043e\u043c \u043a\u043d\u043e\u043f\u043a\u0438. \u041c\u0435\u0442\u043e\u0434 \u043c\u043e\u043b\u0447\u0430 \u043f\u0440\u043e\u0447\u0438\u0442\u0430\u0435\u0442 \u0447\u0443\u0436\u043e\u0435 name<\/code> (undefined<\/code> \u0438\u043b\u0438 \u043f\u0443\u0441\u0442\u0443\u044e \u0441\u0442\u0440\u043e\u043a\u0443) \u0432\u043c\u0435\u0441\u0442\u043e \"\u0410\u043d\u043d\u0430\"<\/code>, \u0438 \u0442\u0430\u043a\u0443\u044e \u043e\u0448\u0438\u0431\u043a\u0443 \u0437\u0430\u043c\u0435\u0442\u0438\u0442\u044c \u0442\u0440\u0443\u0434\u043d\u0435\u0435, \u0447\u0435\u043c TypeError<\/code>. \u0418\u0441\u043f\u0440\u0430\u0432\u043b\u0435\u043d\u0438\u044f — bind<\/code> \u0438\u043b\u0438 \u043e\u0431\u0435\u0440\u0442\u043a\u0430-\u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f.<\/p>\n
    \u0421\u0442\u0440\u043e\u043a\u0430 \u042f undefined<\/code> — \u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u0435 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u043e\u0439 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u0432 \u0440\u043e\u043b\u0438 \u043c\u0435\u0442\u043e\u0434\u0430: this<\/code> \u0432\u0437\u044f\u0442 \u0438\u0437 \u043a\u043e\u0434\u0430 \u0432\u043e\u043a\u0440\u0443\u0433 \u043e\u0431\u044a\u0435\u043a\u0442\u0430. \u0412 Node.js \u0432 \u0444\u043e\u0440\u043c\u0430\u0442\u0435 CommonJS \u044d\u0442\u043e \u043f\u0443\u0441\u0442\u043e\u0439 module.exports<\/code>, \u0432 \u0431\u0440\u0430\u0443\u0437\u0435\u0440\u043d\u043e\u043c \u0441\u043a\u0440\u0438\u043f\u0442\u0435 — window<\/code>, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 \u0437\u0430\u0432\u0438\u0441\u0438\u0442 \u043e\u0442 \u0441\u0440\u0435\u0434\u044b. \u0412\u044b\u0432\u043e\u0434: \u043c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u0435\u043a\u0442\u0430 \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u0442\u044c \u043a\u0440\u0430\u0442\u043a\u043e\u0439 \u0437\u0430\u043f\u0438\u0441\u044c\u044e greet() {}<\/code>, \u0430 \u043d\u0435 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u043e\u0439.<\/p>\n
    \u0413\u0434\u0435 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f \u043a\u0430\u043a \u0440\u0430\u0437 \u043d\u0443\u0436\u043d\u0430<\/h3>\n
    \"use strict\"<\/span>;<\/span>\n\nconst<\/span> <\/span>timer<\/span> <\/span>=<\/span> {<\/span>\n  <\/span>seconds<\/span>:<\/span> <\/span>0<\/span>,<\/span>\n  <\/span>startBroken<\/span>() {<\/span>\n    [<\/span>1<\/span>, <\/span>2<\/span>, <\/span>3<\/span>].<\/span>forEach<\/span>(<\/span>function<\/span> () {<\/span>\n      <\/span>this<\/span>.<\/span>seconds<\/span> <\/span>+=<\/span> <\/span>1<\/span>;   <\/span>\/\/ \u043e\u0431\u044b\u0447\u043d\u0430\u044f \u0444\u0443\u043d\u043a\u0446\u0438\u044f: \u0441\u0432\u043e\u0439 this, \u043d\u0435 timer<\/span>\n    });<\/span>\n  },<\/span>\n  <\/span>start<\/span>() {<\/span>\n    [<\/span>1<\/span>, <\/span>2<\/span>, <\/span>3<\/span>].<\/span>forEach<\/span>(() => {<\/span>\n      <\/span>this<\/span>.<\/span>seconds<\/span> <\/span>+=<\/span> <\/span>1<\/span>;   <\/span>\/\/ \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0431\u0435\u0440\u0435\u0442 this \u0438\u0437 \u043c\u0435\u0442\u043e\u0434\u0430 start<\/span>\n    });<\/span>\n  },<\/span>\n};<\/span>\n\ntry<\/span> {<\/span>\n  <\/span>timer<\/span>.<\/span>startBroken<\/span>();<\/span>\n} <\/span>catch<\/span> (<\/span>e<\/span>) {<\/span>\n  <\/span>console<\/span>.<\/span>log<\/span>(<\/span>e<\/span>.<\/span>name<\/span> <\/span>+<\/span> <\/span>\": \"<\/span> <\/span>+<\/span> <\/span>e<\/span>.<\/span>message<\/span>);<\/span>\n}<\/span>\ntimer<\/span>.<\/span>start<\/span>();<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>timer<\/span>.<\/span>seconds<\/span>);<\/span><\/code><\/pre>\n
    TypeError: Cannot read properties of undefined (reading 'seconds')\n3\n<\/code><\/pre>\n
    \u0412\u043d\u0443\u0442\u0440\u0438 \u043c\u0435\u0442\u043e\u0434\u0430 \u043a\u043e\u043b\u0431\u044d\u043a \u043b\u0443\u0447\u0448\u0435 \u043f\u0438\u0441\u0430\u0442\u044c \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u044b\u043c: \u043e\u043d \u0432\u0438\u0434\u0438\u0442 this<\/code> \u043c\u0435\u0442\u043e\u0434\u0430. \u0412 \u043d\u0435\u0441\u0442\u0440\u043e\u0433\u043e\u043c \u0440\u0435\u0436\u0438\u043c\u0435 startBroken<\/code> \u043d\u0435 \u0443\u043f\u0430\u043b \u0431\u044b, \u0430 \u043c\u043e\u043b\u0447\u0430 \u0437\u0430\u043f\u0438\u0441\u0430\u043b NaN<\/code> \u0432 \u0433\u043b\u043e\u0431\u0430\u043b\u044c\u043d\u044b\u0439 \u043e\u0431\u044a\u0435\u043a\u0442 — \u0442\u0430\u043a\u0443\u044e \u043e\u0448\u0438\u0431\u043a\u0443 \u0438\u0441\u043a\u0430\u0442\u044c \u0434\u043e\u043b\u044c\u0448\u0435.<\/p>\n
    \u041c\u0435\u0442\u043e\u0434\u044b \u043a\u043b\u0430\u0441\u0441\u0430, \u0433\u0435\u0442\u0442\u0435\u0440\u044b \u0438 \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0435 \u043c\u0435\u0442\u043e\u0434\u044b<\/h2>\n
    \u0412 \u043a\u043b\u0430\u0441\u0441\u0430\u0445 \u043c\u0435\u0442\u043e\u0434\u044b \u043e\u0431\u044a\u044f\u0432\u043b\u044f\u044e\u0442\u0441\u044f \u0442\u043e\u0439 \u0436\u0435 \u043a\u0440\u0430\u0442\u043a\u043e\u0439 \u0437\u0430\u043f\u0438\u0441\u044c\u044e. \u0414\u043e\u0431\u0430\u0432\u043b\u044f\u044e\u0442\u0441\u044f \u0434\u0432\u0430 \u0432\u0438\u0434\u0430: \u0433\u0435\u0442\u0442\u0435\u0440 (\u0447\u0438\u0442\u0430\u0435\u0442\u0441\u044f \u043a\u0430\u043a \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e) \u0438 \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u043c\u0435\u0442\u043e\u0434 (\u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0443 \u0441\u0430\u043c\u043e\u0433\u043e \u043a\u043b\u0430\u0441\u0441\u0430).<\/p>\n
    class<\/span> <\/span>Counter<\/span> {<\/span>\n  <\/span>#value<\/span> <\/span>=<\/span> <\/span>0<\/span>;                 <\/span>\/\/ \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0435 \u043f\u043e\u043b\u0435<\/span>\n\n  <\/span>increment<\/span>(<\/span>step<\/span> <\/span>=<\/span> <\/span>1<\/span>) {       <\/span>\/\/ \u043c\u0435\u0442\u043e\u0434 \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u0430<\/span>\n    <\/span>this<\/span>.<\/span>#value<\/span> <\/span>+=<\/span> <\/span>step<\/span>;<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>;              <\/span>\/\/ \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u043c \u043e\u0431\u044a\u0435\u043a\u0442 - \u0432\u044b\u0437\u043e\u0432\u044b \u043c\u043e\u0436\u043d\u043e \u0441\u0446\u0435\u043f\u0438\u0442\u044c<\/span>\n  }<\/span>\n\n  <\/span>get<\/span> <\/span>value<\/span>() {               <\/span>\/\/ \u0433\u0435\u0442\u0442\u0435\u0440: \u0447\u0438\u0442\u0430\u0435\u0442\u0441\u044f \u043a\u0430\u043a \u0441\u0432\u043e\u0439\u0441\u0442\u0432\u043e, \u0431\u0435\u0437 \u0441\u043a\u043e\u0431\u043e\u043a<\/span>\n    <\/span>return<\/span> <\/span>this<\/span>.<\/span>#value<\/span>;<\/span>\n  }<\/span>\n\n  <\/span>static<\/span> <\/span>from<\/span>(<\/span>n<\/span>) {            <\/span>\/\/ \u0441\u0442\u0430\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u043c\u0435\u0442\u043e\u0434: \u0432\u044b\u0437\u044b\u0432\u0430\u0435\u0442\u0441\u044f \u0443 \u043a\u043b\u0430\u0441\u0441\u0430<\/span>\n    <\/span>return<\/span> <\/span>new<\/span> <\/span>Counter<\/span>().<\/span>increment<\/span>(<\/span>n<\/span>);<\/span>\n  }<\/span>\n}<\/span>\n\nconst<\/span> <\/span>c<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Counter<\/span>();<\/span>\nc<\/span>.<\/span>increment<\/span>().<\/span>increment<\/span>(<\/span>5<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>c<\/span>.<\/span>value<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Counter<\/span>.<\/span>from<\/span>(<\/span>10<\/span>).<\/span>value<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>typeof<\/span> <\/span>c<\/span>.<\/span>increment<\/span>, <\/span>typeof<\/span> <\/span>Counter<\/span>.<\/span>from<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Object<\/span>.<\/span>keys<\/span>(<\/span>c<\/span>));<\/span><\/code><\/pre>\n
    6\n10\nfunction function\n[]\n<\/code><\/pre>\n
    Object.keys(c)<\/code> \u043f\u0443\u0441\u0442: \u043c\u0435\u0442\u043e\u0434\u044b \u043a\u043b\u0430\u0441\u0441\u0430 \u0445\u0440\u0430\u043d\u044f\u0442\u0441\u044f \u043d\u0435 \u0432 \u0441\u0430\u043c\u043e\u043c \u043e\u0431\u044a\u0435\u043a\u0442\u0435, \u0430 \u0432 \u0435\u0433\u043e \u043f\u0440\u043e\u0442\u043e\u0442\u0438\u043f\u0435 (Counter.prototype<\/code>), \u043e\u0431\u0449\u0435\u043c \u0434\u043b\u044f \u0432\u0441\u0435\u0445 \u044d\u043a\u0437\u0435\u043c\u043f\u043b\u044f\u0440\u043e\u0432, \u0430 \u043f\u0440\u0438\u0432\u0430\u0442\u043d\u043e\u0435 \u043f\u043e\u043b\u0435 #value<\/code> \u0432 \u0441\u043f\u0438\u0441\u043e\u043a \u043a\u043b\u044e\u0447\u0435\u0439 \u043d\u0435 \u043f\u043e\u043f\u0430\u0434\u0430\u0435\u0442.<\/p>\n
    \u0412\u0441\u0442\u0440\u043e\u0435\u043d\u043d\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b, \u043a\u043e\u0442\u043e\u0440\u044b\u0435 \u043d\u0443\u0436\u043d\u044b \u0441 \u043f\u0435\u0440\u0432\u043e\u0433\u043e \u0434\u043d\u044f<\/h2>\n
    const<\/span> <\/span>s<\/span> <\/span>=<\/span> <\/span>\"  JavaScript  \"<\/span>;<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>s<\/span>.<\/span>trim<\/span>().<\/span>length<\/span>);<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>s<\/span>.<\/span>trim<\/span>().<\/span>toLowerCase<\/span>());<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>\"otus.ru\"<\/span>.<\/span>includes<\/span>(<\/span>\"otus\"<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>\"a-b-c\"<\/span>.<\/span>split<\/span>(<\/span>\"-\"<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>((<\/span>3.14159<\/span>).<\/span>toFixed<\/span>(<\/span>2<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Number<\/span>.<\/span>parseInt<\/span>(<\/span>\"42px\"<\/span>, <\/span>10<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>Math<\/span>.<\/span>round<\/span>(<\/span>2.5<\/span>), <\/span>Math<\/span>.<\/span>round<\/span>(<\/span>-<\/span>2.5<\/span>));<\/span>\nconst<\/span> <\/span>d<\/span> <\/span>=<\/span> <\/span>new<\/span> <\/span>Date<\/span>(<\/span>Date<\/span>.<\/span>UTC<\/span>(<\/span>2026<\/span>, <\/span>8<\/span>, <\/span>24<\/span>));<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>d<\/span>.<\/span>toISOString<\/span>());<\/span>\nconsole<\/span>.<\/span>log<\/span>(<\/span>d<\/span>.<\/span>getUTCMonth<\/span>());<\/span><\/code><\/pre>\n
    10\njavascript\ntrue\n[ 'a', 'b', 'c' ]\n3.14\n42\n3 -2\n2026-09-24T00:00:00.000Z\n8\n<\/code><\/pre>\n
    \u0414\u0432\u0435 \u043b\u043e\u0432\u0443\u0448\u043a\u0438 \u0438\u0437 \u044d\u0442\u043e\u0433\u043e \u0432\u044b\u0432\u043e\u0434\u0430. Math.round<\/code> \u043e\u043a\u0440\u0443\u0433\u043b\u044f\u0435\u0442 \u043f\u043e\u043b\u043e\u0432\u0438\u043d\u0443 \u0432 \u0441\u0442\u043e\u0440\u043e\u043d\u0443 \u043f\u043b\u044e\u0441 \u0431\u0435\u0441\u043a\u043e\u043d\u0435\u0447\u043d\u043e\u0441\u0442\u0438, \u043f\u043e\u044d\u0442\u043e\u043c\u0443 -2.5<\/code> \u0434\u0430\u0435\u0442 -2<\/code>, \u0430 \u043d\u0435 -3<\/code>. \u041c\u0435\u0441\u044f\u0446\u044b \u0432 Date<\/code> \u0441\u0447\u0438\u0442\u0430\u044e\u0442\u0441\u044f \u0441 \u043d\u0443\u043b\u044f: \u0441\u0435\u043d\u0442\u044f\u0431\u0440\u044c — \u044d\u0442\u043e 8<\/code>. toFixed<\/code> \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u0442 \u0441\u0442\u0440\u043e\u043a\u0443, \u0430 \u043d\u0435 \u0447\u0438\u0441\u043b\u043e.<\/p>\n
    \u041c\u0435\u0442\u043e\u0434\u044b \u0441\u0442\u0440\u043e\u043a \u043d\u0435 \u043c\u0435\u043d\u044f\u044e\u0442 \u0438\u0441\u0445\u043e\u0434\u043d\u0443\u044e \u0441\u0442\u0440\u043e\u043a\u0443, \u0430 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u044e\u0442 \u043d\u043e\u0432\u0443\u044e: \u0441\u0442\u0440\u043e\u043a\u0438 \u0432 JavaScript \u043d\u0435\u0438\u0437\u043c\u0435\u043d\u044f\u0435\u043c\u044b. \u0421\u0442\u0430\u0440\u044b\u0435 \u043c\u0435\u0442\u043e\u0434\u044b \u0432\u0440\u043e\u0434\u0435 bold()<\/code>, blink()<\/code>, fontcolor()<\/code> \u0438 document.write()<\/code> \u0438\u0437 \u0443\u0447\u0435\u0431\u043d\u0438\u043a\u043e\u0432 2000-\u0445 \u0441\u043e\u0445\u0440\u0430\u043d\u0435\u043d\u044b \u0434\u043b\u044f \u0441\u043e\u0432\u043c\u0435\u0441\u0442\u0438\u043c\u043e\u0441\u0442\u0438, \u043d\u043e \u0432 \u043d\u043e\u0432\u043e\u043c \u043a\u043e\u0434\u0435 \u043d\u0435 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u044e\u0442\u0441\u044f: \u0440\u0430\u0437\u043c\u0435\u0442\u043a\u0443 \u043c\u0435\u043d\u044f\u044e\u0442 \u0447\u0435\u0440\u0435\u0437 DOM (textContent<\/code>, classList<\/code>).<\/p>\n
    \u0415\u0441\u043b\u0438 \u043d\u0435 \u043f\u043e\u043b\u0443\u0447\u0438\u043b\u043e\u0441\u044c: \u0441\u0438\u043c\u043f\u0442\u043e\u043c -> \u043f\u0440\u0438\u0447\u0438\u043d\u0430<\/h2>\n\n\n\n\n\n\n\n\n\n\n
    \u0421\u0438\u043c\u043f\u0442\u043e\u043c<\/th>\n\u0427\u0430\u0441\u0442\u0430\u044f \u043f\u0440\u0438\u0447\u0438\u043d\u0430<\/th>\n\u0427\u0442\u043e \u0441\u0434\u0435\u043b\u0430\u0442\u044c<\/th>\n<\/tr>\n<\/thead>\n
    Cannot read properties of undefined (reading '...')<\/code> \u0432\u043d\u0443\u0442\u0440\u0438 \u043c\u0435\u0442\u043e\u0434\u0430<\/td>\n\u043c\u0435\u0442\u043e\u0434 \u0432\u044b\u0437\u0432\u0430\u043d \u0431\u0435\u0437 \u0442\u043e\u0447\u043a\u0438 \u0438\u043b\u0438 \u043f\u0435\u0440\u0435\u0434\u0430\u043d \u043a\u043e\u043b\u0431\u044d\u043a\u043e\u043c<\/td>\nbind(obj)<\/code> \u0438\u043b\u0438 () => obj.method()<\/code><\/td>\n<\/tr>\n
    \u041c\u0435\u0442\u043e\u0434 \u0432\u043e\u0437\u0432\u0440\u0430\u0449\u0430\u0435\u0442 undefined<\/code><\/td>\n\u043d\u0435\u0442 return<\/code> \u0438\u043b\u0438 \u0441\u0442\u0440\u0435\u043b\u043e\u0447\u043d\u0430\u044f \u0441 {}<\/code><\/td>\n\u0434\u043e\u0431\u0430\u0432\u0438\u0442\u044c return<\/code><\/td>\n<\/tr>\n
    \u0412 \u043a\u043e\u043d\u0441\u043e\u043b\u0438 \u0442\u0435\u043a\u0441\u0442 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 \u0432\u043c\u0435\u0441\u0442\u043e \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442\u0430<\/td>\n\u0437\u0430\u0431\u044b\u0442\u044b \u0441\u043a\u043e\u0431\u043a\u0438 \u0432\u044b\u0437\u043e\u0432\u0430<\/td>\nobj.method()<\/code>, \u0430 \u043d\u0435 obj.method<\/code><\/td>\n<\/tr>\n
    Cannot access 'x' before initialization<\/code><\/td>\n\u043e\u0431\u0440\u0430\u0449\u0435\u043d\u0438\u0435 \u043a let<\/code>\/const<\/code> \u0434\u043e \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u044f<\/td>\n\u043f\u0435\u0440\u0435\u043d\u0435\u0441\u0442\u0438 \u043e\u0431\u044a\u044f\u0432\u043b\u0435\u043d\u0438\u0435 \u0432\u044b\u0448\u0435<\/td>\n<\/tr>\n
    Assignment to constant variable<\/code><\/td>\n\u043f\u0435\u0440\u0435\u043f\u0440\u0438\u0441\u0432\u0430\u0438\u0432\u0430\u043d\u0438\u0435 const<\/code><\/td>\nlet<\/code>, \u0435\u0441\u043b\u0438 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u0434\u043e\u043b\u0436\u043d\u043e \u043c\u0435\u043d\u044f\u0442\u044c\u0441\u044f<\/td>\n<\/tr>\n
    ... is not a function<\/code><\/td>\n\u043e\u043f\u0435\u0447\u0430\u0442\u043a\u0430 \u0432 \u0438\u043c\u0435\u043d\u0438 \u043c\u0435\u0442\u043e\u0434\u0430 \u0438\u043b\u0438 \u0443 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u044f \u043d\u0435\u0442 \u0442\u0430\u043a\u043e\u0433\u043e \u043c\u0435\u0442\u043e\u0434\u0430<\/td>\n\u043f\u0440\u043e\u0432\u0435\u0440\u0438\u0442\u044c typeof obj.method<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
    \u0412\u044b\u0432\u043e\u0434\u044b<\/h2>\n