Matukio ya Mtu wa ES5

ECMAScript 5 (2009) walifanya kwa JavaScript kipya kwa kumekuwa na vifaa vya kifaa kwa sababu ya kufikia.

Kumalisha kinaobject

// Kuunda kinaobject kwa kuzingatia kinaobject kinafuata
Object.create()
// Kuongeza au kurekeza tabia kinaobject
Object.defineProperty(object, property, descriptor)
// Kuongeza au kurekeza tabia kinaobject
Object.defineProperties(object, descriptors)
// Kuagiza tabia
Object.getOwnPropertyDescriptor(object, property)
// Inatoa orodha ya tabia zote
Object.getOwnPropertyNames(object)
// Kuagiza prototipo
Object.getPrototypeOf(object)
// Inatoa orodha ya tabia zilizotumika
Object.keys(object)

Kuproteja kinaobject

// Kupunguza kuingiza tabia kinaobject
Object.preventExtensions(object)
// Ikiwa tabia inaweza kuongezwa kinaobject, ita kuwa true
Object.isExtensible(object)
// Kupunguza kumwambia kinaobject kila muhimu (hakupewa thamani)
Object.seal(object)
// Ikiwa kinaobject kinahifadhiwa, ita kuwa true
Object.isSealed(object)
// Kupunguza kumwambia kinaobject kila muhimu
Object.freeze(object)
// Ikiwa kinaobject kinafichwa, ita kuwa true
Object.isFrozen(object)

Kurekeza thamani ya tabia

Inafuatilia

Object.defineProperty(object, property, {value : value)

mimba

Mfano huu kurekeza tabia ya thamani:

const person = {
  firstName: "Bill",
  lastName : "Gates",
  language : "EN"
};
// Kurekeza tabia
Object.defineProperty(person, "language", {value : "NO"});

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Kumwambia meta-data

ES5 inahidi kwa kumwambia meta-data ya tabia zifuatavyoke:

writable : true      // 属性值可更改
enumerable : true    // 属性可枚举
configurable : true  // 属性可重新配置

writable : false     // 属性值不可更改
enumerable : false   // 属性不可枚举
configurable : false // mafanikio hayakufanyiwa mabadiliko

ES5 inaonesha kusasaabisha getter na setter:

// kuwa mtaaliko
get: function() { return language }
// kuwa mtaaliko
set: function(value) { language = value }

Mfano hii inasababisha language kuwa bila hatua:

Object.defineProperty(person, "language", {writable:false});

Mfano hii inasababisha language kuingia kama mafanikio yenye muhimu:

Object.defineProperty(person, "language", {enumerable:false});

Kuonyesha mafanikio yote

Mfano hii inaonyesha mafanikio ya kiume yote:

mimba

const person = {
  firstName: "Bill",
  lastName : "Gates",
  language : "EN"
};
Object.defineProperty(person, "language", {enumerable:false});
Object.getOwnPropertyNames(person);  // kuwaarifu taarifa ya mafanikio ya kiume

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Kuonyesha mafanikio yenye muhimu

Mfano hii inaonyesha mafanikio yenye muhimu ya kiume:

mimba

const person = {
  firstName: "Bill",
  lastName : "Gates",
  language : "EN"
};
Object.defineProperty(person, "language", {enumerable:false});
Object.keys(person);  // kuwaarifu taarifa ya mafanikio yenye muhimu

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Ongeza mafanikio

Mfano hii inaongeza mafanikio mpya kwa kiume:

mimba

// kuanzisha kiume
const person = {
  firstName: "Bill",
  lastName : "Gates",
  language : "EN"
};
// Ongeza mafanikio
Object.defineProperty(person, "year", {value:"2008"});

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Ongeza Getter na Setter

Object.defineProperty() Methodu huzingatia kuongeza Getter na Setter:

mimba

// kuanzisha kiume
const person = {firstName:"Bill", lastName:"Gates"};
// kuwa mtaaliko
Object.defineProperty(person, "fullName", {
  get: function () {return this.firstName + " " + this.lastName;}
});

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mimba ya kinalesha

// kuwa kiume
const obj = {counter:0};
// kuwa mtaaliko
Object.defineProperty(obj, "reset", {
  get : function () {this.counter = 0;}
});
Object.defineProperty(obj, "increment", {
  get : function () {this.counter++;}
});
Object.defineProperty(obj, "decrement", {
  get : function () {this.counter--;}
});
Object.defineProperty(obj, "add", {
  set : function (value) {this.counter += value;}
});
Object.defineProperty(obj, "subtract", {
  set : function (i) {this.counter -= i;}
});
// Tukio la kina:
obj.reset;
obj.add = 5;
obj.subtract = 1;
obj.increment;
obj.decrement;

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