Global Variables vs Local Variables (v3)

Revision 3 of this benchmark created by tsvetomir 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 a,b=0;
      function x() {
        for(a=0;a<20;a++)
          b+=a;
      }
      function y() {
        var c,d=0;
        for(c=0;c<20;c++)
          d+=c;
      }
      function z(){
        var c = a,
            d = b;
    
        for(c=0;c<20;c++)
           d+=c;
      }

Test runner

Ready to run.

Testing in
TestOps/sec
Global variables
x();
ready
Local variables
y();
ready
Cached global variables
z();
ready

Revisions

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