Error.prototype.toString()
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
| Specification |
|---|
| ECMAScript Language Specification # sec-error.prototype.tostring |
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