javascript:声明并立即调用内联函数的原因

Question

所以我有一个采访，我问的是立即声明和调用函数的目的，我无法回答，即:

(function(){

    // code
})();

这样做的原因是什么？

Answer 1

Object-Oriented JavaScript - Second Edition: One good application of immediate (self-invoking) anonymous functions is when you want to have some work done without creating extra global variables. A drawback, of course, is that you cannot execute the same function twice. This makes immediate functions best suited for one-off or initialization tasks.

The syntax may look a little scary at first, but all you do is simply place a function expression inside parentheses followed by another set of parentheses. The second set says "execute now" and is also the place to put any arguments that your anonymous function might accept:

(function() {

})();

或

(function() {

}());

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