‘var’ declarations to the top of the function

JavaScript performance comparison

Test case created by Jerôme


A good pratice is "Move ‘var’ declarations to the top of the function."

Preparation code

Benchmark.prototype.setup = function() {
    function demo1() {
      if (true) {
        var toto = true;
    function demo2() {
      var toto;
      if (true) {
        toto = true;

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

Testing in unknown unknown
Test Ops/sec
Define in the function core
var truc;

truc = demo1();
Define var on top of function
var truc;

truc = demo2();

Compare results of other browsers


You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:


Comment form temporarily disabled.

Add a comment