Javascript 之错误处理篇

从IE4.0以上的版本，渐渐加入错误处理机制，当然，没有错误处理的代码，不够健壮，所以我在这里不得不班门弄斧，谈谈Javascript中的错误处理。

//noneXistentFunction 引发错误处理机制
try{
	window.noneXistentFunction();
	alert("Method completed");
} catch (exception) {
//因为Javascript是弱类型语言，
//所以只能有一个catch语句，
//并不能分类捕获Exception，
//所有的Exception在一个catch中处理
	alert("an exception occurred" + exception.message);
} finally {
	alert("End of try ... catch test");
}

//嵌套 TRY CATCH

try {
	eval("a++b");
} catch (exception) {
	alert("an exception occurrd " + exception.message);
	try {
		var aErrors = new Array(100000000000000000000000000000000000000);
	} catch (exception){
		alert("another exception occurred");
	}
} finally {
	alert("all done");
}

//判断错误类型
try {
	eval("a++b");
} catch (exception) {
//通过NAME 判断
	if(exception.name == "SyntaxError") {
		alert("Syntax Error " + exception.message);
	} else {
		alert("An Unexpected Error Occurred " + exception.message);
	}
	
	try {
		var aErrors = new Array(100000000000000000000000000000000000000);
	} catch (exception){
	//通过 INSTANCEOF 判断
		if(exception instanceof SyntaxError) {
			alert("Syntax Error " + exception.message);
		} else if (exception instanceof EvalError){
			alert("Eval Function Error " + exception.message);
		} else if (exception instanceof ReferenceError){
			alert("Reference Error " + exception.message);
		} else if (exception instanceof RangeError){
			alert("Number Range Error " + exception.message);
		} else if (exception instanceof TypeError){
			alert("variable Type Error " + exception.message);
		} else if (exception instanceof URIError){
			alert("encodeURI or decodeURI Function Error " + exception.message);
		} else {
			alert("An Unexpected Error Occurred " + exception.message);
		}
	}
} finally {
	alert("all done");
}