Beginning Web Development, Silverlight, and ASP.NET AJAX

CHAPTER 14 ■ JAVASCRIPT PROGRAMMING WITH ASP.NET AJAX 347
var a = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
var b = Array.indexOf(a,'Item 2')
// returns '1'
Inserting an Item into an Array
Earlier, you saw the add command, which adds an item at the end of the array. If you want
to add an item at a specific location within the array, you can use the insert function. It
takes three parameters:
Array: The array that you are inserting the item into
Index: The location where you want to insert it (zero-based)
Item: The item to insert
var a = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
Array.insert(a,1,'Item 1a');
// Results: 'Item 1', 'Item 1a', 'Item 2', 'Item 3', 'Item 4'
Removing an Item from an Array
There are two methods for removing items from an array. The remove method takes an
item as a parameter and removes the first instance of that item from the array, returning
true when successful and false otherwise.
var a = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
Array.remove(a,'Item 2');
// will remove 'Item 2' from the array
The removeAt function removes the item at the specified index from the array.
var a = ['Item 1', 'Item 2', 'Item 3', 'Item 4'];
Array.removeAt(a,1);
// will also remove 'Item 2' from the array