Global Variables vs Local Variables (v17)

Revision 17 of this benchmark created by Md Khan on

Description

This test compares the performance of global variables to local variables within functions.

Global variables should be slower because they do not exist in a function's activation object. JavaScript must traverse the Scope Chain to locate global variables.

Setup

var myArr = [];
        for(var i = 0; i< 1000; i++){
         myArr[i]=i;
       }
    
        function useGlobal() {
            for (j = 0; j < 1000; j++)
                console.log(myArr[j]);
        }
    
        function useLocal() {
            var localArr = myArr;
            for (var k = 0; k < 1000; k++)
                console.log(localArr[k]);
        }

Test runner

Ready to run.

Testing in
TestOps/sec
Global variables
useGlobal();
ready
Local variables
useLocal();
ready

Revisions

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