Object.prototype.toSource()

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句法
描述
范例
规范
浏览器兼容性
另请参阅
相关话题

过时
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.

toSource() method returns a string representing the source code of the object.

句法

Object.toSource();
obj.toSource();

返回值

A string representing the source code of the object.

描述

toSource() method returns the following values:

For the built-in Object 对象， toSource() returns the following string indicating that the source code is not available:
```
function Object() {
    [native code]
}
							
```
For instances of Object , toSource() returns a string representing the source code.

可以调用 toSource() while debugging to examine the contents of an object.

Overriding the `toSource()` 方法

It is safe for objects to override the toSource() method. For example:

function Person(name) {
  this.name = name;
}
Person.prototype.toSource = function Person_toSource() {
  return 'new Person(' + uneval(this.name) + ')';
};
console.log(new Person('Joe').toSource()); // ---> new Person("Joe")

Built-in `toSource()` methods

Each core JavaScript type has its own toSource() method. These objects are:

Array.prototype.toSource() — Array 对象。
Boolean.prototype.toSource() — 布尔 对象。
Date.prototype.toSource() — Date 对象。
Function.prototype.toSource() — Function 对象。
Number.prototype.toSource() — Number 对象。
RegExp.prototype.toSource() — RegExp 对象。
String.prototype.toSource() — String 对象。
Symbol.prototype.toSource() — Symbol 对象。
Math.toSource() — Returns the String "Math".

Limitations on cyclical objects

In the case of objects that contain references to themselves, e.g. a cyclically linked list or a tree that can be traversed both ways, toSource() will not recreate the self-reference, as of Firefox 24. For example:

var obj1 = {};
var obj2 = { a: obj1 };
obj1.b = obj2;
console.log('Cyclical: ' + (obj1.b.a == obj1));
var objSource = obj1.toSource(); // returns "({b:{a:{}}})"
obj1 = eval(objSource);
console.log('Cyclical: ' + (obj1.b.a == obj1));

If a cyclical structure is employed and toSource() is needed, the object must provide an override to toSource() , either using a reference to a constructor or providing an anonymous function.

范例

使用 `toSource()`

The following code defines the Dog object type and creates theDog , an object of type Dog :

function Dog(name, breed, color, sex) {
  this.name = name;
  this.breed = breed;
  this.color = color;
  this.sex = sex;
}
theDog = new Dog('Gabby', 'Lab', 'chocolate', 'female');

Calling the toSource() 方法为 theDog displays the JavaScript source that defines the object:

theDog.toSource();
// returns ({name:"Gabby", breed:"Lab", color:"chocolate", sex:"female"})

规范

Not part of any standard.

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`toSource` 弃用非标	Chrome No	Edge No	Firefox 1 — 74 1 — 74 Starting in Firefox 74, `toSource()` is no longer available for use by web content. It is still allowed for internal and privileged code.	IE No	Opera No	Safari No	WebView Android No	Chrome Android No	Firefox Android 4	Opera Android No	Safari iOS No	Samsung Internet Android No	nodejs No

图例

完整支持
不支持

弃用。不要用于新网站。

另请参阅

Object.prototype.toString()

元数据

最后修改： May 19, 2020

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句法

返回值

描述

Overriding the toSource() 方法

Built-in toSource() methods