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.prototype
- Allows 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.constructor
- Specifies the function that created an instance's prototype.
ReferenceError.prototype.message
- Error message. Although ECMA-262 specifies that
ReferenceError
should provide its ownmessage
property, in SpiderMonkey, it inheritsError.prototype.message
. ReferenceError.prototype.name
- Error name. Inherited from
Error
. ReferenceError.prototype.fileName
- Path to file that raised this error. Inherited from
Error
. ReferenceError.prototype.lineNumber
- Line number in file that raised this error. Inherited from
Error
. ReferenceError.prototype.columnNumber
- Column number in line that raised this error. Inherited from
Error
. ReferenceError.prototype.stack
- Stack 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" }