Arrays

An array is an ordered set of values. You can refer to the array elements with a name and index. These are the three ways to create arrays in JavaScript:

var arr = new Array(1,2,3);
var arr = Array(1,2,3);
var arr = [1,2,3];

When these values are specified, the array is initialized with them as the array's elements. An array's length property is equal to the number of arguments. The bracket syntax is called an array literal. It's a shorter and preferred way to initialize arrays.

You have to use the array literal syntax if you want to initialize an array with a single element and the element happens to be a number. If you pass a single number value to the Array() constructor or function, JavaScript considers this parameter as the length of the array, not as a single element:

var arr = [10];
var arr = Array(10); // Creates an array with no element, but with arr.length set to 10
// The above code is equivalent to
var arr = [];
arr.length = 10;

JavaScript does not have an explicit array data...