ReferenceError

ReferenceError（引用错误）对象代表当一个不存在的变量被引用时发生的错误。

语法

new ReferenceError([message[, fileName[, lineNumber]]])

参数

message可选。描述可读的错误信息fileName可选。包含引起异常代码的文件名lineNumber可选。引起异常的代码行号

描述

当你尝试引用一个未被定义的变量时，将会抛出一个ReferenceError。

属性

ReferenceError.prototypeAllows the addition of properties to an ReferenceError object.

方法

全局的ReferenceError本身并不包含有方法，但是他可以从原型链上继承一些方法

ReferenceError实例

属性

ReferenceError.prototype.constructorSpecifies the function that created an instance's prototype.ReferenceError.prototype.messageError message. Although ECMA-262 specifies that ReferenceError should provide its own message property, in SpiderMonkey, it inherits Error.prototype.message.ReferenceError.prototype.nameError name. Inherited from Error.ReferenceError.prototype.fileNamePath to file that raised this error. Inherited from Error.ReferenceError.prototype.lineNumberLine number in file that raised this error. Inherited from Error.ReferenceError.prototype.columnNumberColumn number in line that raised this error. Inherited from Error.ReferenceError.prototype.stackStack trace. Inherited from Error.

方法

Although the ReferenceError prototype object does not contain any methods of its own,ReferenceError instances do inherit some methods through the prototype chain.

例子

例:捕获一个ReferenceError

try {
  var a = undefinedVariable;
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message);                   // "undefinedVariable is not defined"
  console.log(e.name);                      // "ReferenceError"
  console.log(e.fileName);                  // "Scratchpad/1"
  console.log(e.lineNumber);                // 2
  console.log(e.columnNumber);              // 6
  console.log(e.stack);                     // "@Scratchpad/2:2:7\n"
}

例:创建一个ReferenceError

try {
  throw new ReferenceError('Hello', 'someFile.js', 10);
} catch (e) {
  console.log(e instanceof ReferenceError); // true
  console.log(e.message);                   // "Hello"
  console.log(e.name);                      // "ReferenceError"
  console.log(e.fileName);                  // "someFile.js"
  console.log(e.lineNumber);                // 10
  console.log(e.columnNumber);              // 0
  console.log(e.stack);                     // "@Scratchpad/2:2:9\n"
}

鹏仔微信 15129739599 鹏仔QQ344225443 鹏仔前端 pjxi.com 共享博客 sharedbk.com