ECMAScript 5 Array Methods

ECMAScript 5 defines nine new array methods for iterating, mapping, filtering, testing, reducing, and searching arrays. Most of the methods accept a function as their first argument and invoke that function once for each element (or at least some elements) of the array. In most cases, the function you supply is invoked with three arguments: the value of the array element, the index of the array element, and the array itself. Often, you only need the first of these argument values and can ignore the second and third values. Most of the ECMAScript 5 array methods that accept a function as their first argument accept an optional second argument. If specified, the function is invoked as if it is a method of ....this