捕获程序异常之tryCatch

一、try catch语法
try…catch…finally…语法中除了try以外，catch和finally都是可选的（两者必须要有一个），也就是说try…catch…finally…语法有以下三种形式。

形式1

try{
//do something
}
catch(e){
//somecode
}
finally{
//do something
}

形式2

try{
//do something
}
catch(e){
//somecode
}

形式3

try{
//do something
}
finally{
//do something
}

二、try catch用法
避免在循环中使用try-catch-finally

var $myObj = ['foo', 'bar'], i;  

//不好的用法
for (i = 0, len = $myObj.length; i <len; i++) {  
    try {  
        // do something that throws an exception 
    }  
    catch (e) {   
        // handle exception  
    } 
}

//好的用法
try { 
    for (i = 0, len = $myObj.length; i <len; i++) {  
        // do something that throws an exception 
    } 
} 
catch (e) {   
   window.location.href = "http://stackoverflow.com/search?q=[js]+" + e.message;
}