MooTools and Array prototype

Question

Mootools is overridding the Array prototype, and the problem is that this prototype and I have an external .js (a library that I can't modify manually) that iterates using for(i in someArray) and it is throwing exception, since now Array has more properties. Any ideas of how to overcome this problem ? I was thinking about removing those properties from array on the Mootools library itself, but it seems is not that easy.

Answer 1

First of all, you should use a regular for(var i=0; i < arr.length; i++) { var el = arr[i]; } loop on arrays.

If you really need for..in and you are working in modern browsers, then you can modify the modification to the prototype to make it non-enumerable.

//Logger function
function logArray(arr) {
    console.log("--TEST-START--");
    for (var i in arr) {
      console.log(arr[i])
    }
    console.log("--TEST-END--");
  }
  //Modify prototype
Array.prototype.a = {
  b: 0
};
//List to test against
var list = [1, 2, 3, 4];
//Log initial list
logArray(list);
//Modify prototype modificiation
Object.defineProperty(Array.prototype, 'a', {
  enumerable: false
});

//Log initial list
logArray(list);