JavaScript ayaa maamusha shabakadda - ECMAScript, oo ah xudunta luqadda, ayaa bislaanaysa. Tilmaamaha cusub (ES6 ama JS2), oo la filayo bartamaha sanadka, ayaa keenaya hal-abuurro badan oo horey loo tijaabin karo. Firefox hadda waxay bixisaa taageerada ugu fiican , laakiin polyfills iyada oo loo marayo transpilers sida Google Traceur ayaa sidoo kale suurtagal ah. Dulmar kooban oo ku saabsan sifooyinka cusub ee ES6 ayaa soo socda.
Ereyga furaha cusub ee wax loo oggol yahay wax badan buu ka fiicanyahay var : Xakamaynta hadda waxay u dhaqantaa sida saxda ah luqadaha kale (C / C ++, Java), waana sababta haddii if-blocks ay hadda sidoo kale leeyihiin baaxad u gaar ah. Saarista, yacni hore u soo qaadista caddeynta isbeddelka ah (maahan qiimeynta) ee baaxadda u gaarka ah sidoo kale waa la dayactiray:
console.log(x); var x = 'foo'; // undefined console.log(y); let y = 'bar'; // not initialized
Liiska hal-abuurka kale waa dheer yahay: joogtada (const), qiimaha caadiga ah ee hawlaha (function pow(a,b=2) { soo celi Math.pow(a,b); }), calaamad cusub oo loogu talagalay hawlaha (ha pow = (a,b=2) => Math.pow(a,b);), shaqooyin badan oo cusub (ku celi(), waxay ka kooban tahay(), startsWith(), find(), findIndex()), qaab-dhismeedka wareegga cusub ee ... ee.
Sidoo kale waxaa xusid mudan noocyada xogta cusub ee Set, Map, Proxy, iyo Symbol, awoodda lagu soo dejiyo (qaybo ka mid ah faylasha kale) JavaScript iyadoo la adeegsanayo 'soo dejinta', iyo hab-raac cusub oo dareen leh oo loogu talagalay fasallada iyo dhaxalka. Badanaa, si kastaba ha ahaatee, waa sifooyinka yaryar laakiin muddada dheer la sugayay sida awoodda lagu daro jebinta xariiqda ee xarfaha qoraalka ah (fiiro gaar ah u yeelo calaamadaha xigashada gaarka ah).:
`foo bar`
JavaScript muddo dheer wuxuu ahaa wax ka badan qalab loogu talagalay xeeladaha yaryar ee mareegaha - waxaa loo isticmaalaa in lagu abuuro barnaamijyo shabakadeed oo awood badan oo waxqabad sare leh oo wax walba u fiican sida kuwa kale ee desktop-ka. Iyada oo ay jiraan astaamo cusub oo waxtar leh iyo taageerada hadda jirta ee ES6, barnaamijintu waa labanlaab ka xiiso badan.
Yaan had iyo jeer rabin inuu hubiyo sinnaanta laba lambar isagoo gacan ka helaya Lambarka cusub ee joogtada ah. EPSILON , oo qiimaheeda uu yahay farqiga u dhexeeya 1 iyo qiimaha dhibcaha soo socda ee sare
let cmp = (a,b) => Math.abs(a-b) < Number.EPSILON;