self-executing-function

问题 In javascript, when would you want to use this: (function(){ //Bunch of code... })(); over this: //Bunch of code... 回答1: Its all about variable scoping. Variables declared in the self executing function are, by default, only available to code within the self executing function. This allows code to be written without concern of how variables are named in other blocks of javascript code. For example: (function(){ var foo = 3; alert(foo); })(); alert(foo); This will first alert "3" and then