Quick and dirty benchmarks of for vs negative while loop in javascript

while-for-bench.js

var i = 100000;
var myArray = [];
while(i--) myArray[i] = i;
myArray[0];

console.log("------- for loop always evaluating length-------")
var forResult = 0; console.time("for"); for(var i=0; i < myArray.length; i++) { forResult += myArray[i] }; console.log("forResult: %i", forResult); console.timeEnd("for");

console.log("------- for loop with length in var-------")
var forResult2 = 0; console.time("for2"); for(var i=0, len = myArray.length; i < len; i++) { forResult2 += myArray[i] }; console.log("forResult2: %i", forResult2); console.timeEnd("for2");

console.log("------- negative while loop -------")
var whileResult = 0; console.time("while"); var j = myArray.length; while(j--) { whileResult += myArray[j] }; console.log("whileResult: %i", whileResult); console.timeEnd("while");