Strings as Arrays

In ECMAScript 5 (and in many recent browser implementations—including IE8—prior to ECMAScript 5), strings behave like read-only arrays. Instead of accessing individual characters with the charAt() method, you can use square brackets:

var s = test;
s.charAt(0)    // => "t"
s[1]           // => "e"

The typeof operator still returns “string” for strings, of course, and the Array.isArray() method returns false if you pass it a string.

The primary benefit of indexable strings is simply that we can replace calls to charAt() with square brackets, which are more concise and readable. The fact that strings behave like arrays also means, however, that we can apply generic array methods to them. For example: