js学习小结（十五）2014.7.22-Javascript中的IIFE--(Immediately Invoked function Expression)

  if declaring  a function like this,and then invoking it immediately,

function foo(){console.log("it is foo");}();

 it will throw a error,

Uncaught SyntaxError: Unexpected token )

but if you just a arguement in the end of the paren,like this

function foo(){console.log("it si foo");}(1);

ok.it won`tl occures any error,but in the same time,the funciton won`t be executed either.because it just equivlent to this:

function foo(){console.log("it si foo");}



(1);

a function declaration followed by a unrelated expression,so you can get it that the function not be executed.

so what does it matter?ok.if you just want to declare a function,and want to execute it right now,you can`t tolerate one second to wait.you shuold know how to implement that.ok,we define the IIFE(Immediately Invoked Function Expression);

http://benalman/news/2010/11/immediately-invoked-function-expression/