Question

I searched for this question but the answers I got not solve my question . Here is my question , I have a array with 10 members .

Js Code

var array = [1,2,3,4,5,6,7,8,9,10];

Loop 1:

for(var i=0,len=array.length;i<len;i++){};

Loop 2

var len = array.length;
for(var i=0;i<len;i++){};

Loop 3

for(var i=0;i<array.length;i++){}

I know there is a major performance difference between 1 and 3 . But , is there any performance difference between 1 and 2 ? .

Answer 1

There shouldn’t be any noticeable difference, although the parsing logic has one more token to parse in example 2.

Shorter is better: var a,b,c,d; should be faster than

var a; var b; var c; var d;