Tutorial Loop Through Array Without Wasteful Lookups
by Unknown in javascript , Tutorial 06 Mar 2014 0
Find the length of the array before using it in the for function, so it doesn't need to count the length of the array each iteration (assuming the length won't be changing mid-loop).
var arLen=myArray.length;
for ( var i=0, len=arLen; i<len; i++ ){
// do something with myArray[i]
}