# Cached and faster `for` loops

faster-for-loops.js

/*
 * The trouble with collections is that they are live queries against the underlying document (the HTML page). This means that every time you access any collection’s length, you’re querying the live DOM, and DOM operations are expensive in general.
 * 
 * It's only good if you don't update the length by f.e. adding DOM nodes
 * 
 * That’s why a better pattern for for loops is to cache the length of the array (or collection) you’re iterating over, as shown in the following example:
 */

for (var i=0, max = myarray.length; i < max; i++) {
	// do sth.
}

// more options:

for (var i=0, max=myarray.length; i < max; i=i+ 1) {
	// do sth.
}

// micro-optimization:

var i, myarray = [];
for (i = myarray.length; i < max; i=i+ 1) {  
   // do sth.  
}