Error.prototype.toString() - JavaScript 编辑

概述

toString() 方法返回一个指定的错误对象（Error object）的字符串表示。

语法

e.toString();

描述

Error 对象覆盖了 Object.prototype.toString() 方法。该方法实现如下：（假定 Object 和 String 没有被更改）：

Error.prototype.toString = function()
{
  "use strict";

  var obj = Object(this);
  if (obj !== this)
    throw new TypeError();

  var name = this.name;
  name = (name === undefined) ? "Error" : String(name);

  var msg = this.message;
  msg = (msg === undefined) ? "" : String(msg);

  if (name === "")
    return msg;
  if (msg === "")
    return name;

  return name + ": " + msg;
};

示例

var e = new Error("fatal error");
print(e.toString()); // "Error: fatal error"

e.name = undefined;
print(e.toString()); // "Error: fatal error"

e.name = "";
print(e.toString()); // "fatal error"

e.message = undefined;
print(e.toString()); // "Error"

e.name = "hello";
print(e.toString()); // "hello"

规范

规范版本	规范状态	注解
ECMAScript 1st Edition.	Standard	Initial definition. Implemented in JavaScript 1.1
ECMAScript 5.1 (ECMA-262) Error.prototype.toString	Standard
ECMAScript 2015 (6th Edition, ECMA-262) Error.prototype.toString	Standard

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Firefox (Gecko)	Internet Explorer	Opera	Safari
Basic support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

Feature	Android	Chrome for Android	Firefox Mobile (Gecko)	IE Mobile	Opera Mobile	Safari Mobile
Basic support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

相关链接

• Error.prototype.toSource()