Javascript array iteration using for..in with MooTools included
for-in-loop, javascript, mootools
Solution
`for..in` is not meant for array iteration. It iterates over all the properties of an object that are not built-in. Since MooTools has added more functions to Array prototype, they are now array properties as well. See this https://developer.mozilla.org/En/Core_JavaScript_1.5_Reference/Statements/For...in
Just use a basic for loop for array iteration.
Problem
I am iterating over an array in MooTools but seeing additional items when iterating through the array using the shorthand `for..in` loop. It works fine when I use the regular `for` loop. Is this a problem with MooTools polluting the global namespace or am I doing something wrong here? There is a `createTabs()` function that iterates over an array and creates a tab for each value in the array: ``` function createTabs() { var myTabs = [["First", "a.png"], ["Second", "b.png"]]; for(var i in myTabs) { var tab = new Tab(myTabs[i][0], myTabs[i][1]); console.log(i); } } ``` This is the output of `console.log(i)`: ``` 0 1 $family each clean associate link contains extend getLast getRandom include combine erase empty flatten hexToRgb rgbToHex toJSON ``` I understand the first 2 indexes, but where is the rest coming from? Edit: Thanks for the quick answers Chetan and k Prime. That makes sense, and the `Array.each` addition by MooTools is much cleaner way to iterate! Looks a lot better now: ``` myTabs.each(function(item) { var tab = new Tab(item[0], item[1]); console.log(item); }); ```