Function definition inside function

Question

If i have code:

function A() {

  function B() {

  }

  B();

}

A();
A();

is B function parsed and created each time i call A(so it can decrease performance of A)?

I'd say yes because function B only exists in the scope of function A — DarkBee, Jul 16 '13 at 07:54
Why don't you make function B outside of A, and call B inside of A? — hevele, Jul 16 '13 at 07:54
Gintas K: i have function and some blocks of code inside that function need to be reused, but just in that function — Krab, Jul 16 '13 at 07:55
I think someone else has already asked the same question: http://stackoverflow.com/questions/6476540/javascript-inner-functions-and-performance — yaoxing, Jul 16 '13 at 07:56

score 2 · Accepted Answer · answered Jul 16 '13 at 08:14

If you want use a function only internally, how about closure. Here an example

    var A = (function () {
    var publicFun = function () { console.log("I'm public"); }
    var privateFun2 = function () { console.log("I'm private"); }

    console.log("call from the inside");
    publicFun();
    privateFun2();

    return {
        publicFun: publicFun
    }
})();   

console.log("call from the outside");
A.publicFun();
A.privateFun(); //error, because this function unavailable

score 2 · Answer 2 · answered Jul 16 '13 at 08:17

2

function A(){

    function B(){

    }
    var F=function(){
        B();
     }
     return F;
}
var X=A();
//Now when u want to use this  just use this X function it will work without parsing B()

answered Jul 16 '13 at 08:17

Robins Gupta

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Function definition inside function

2 Answers2