↑
Main Page

functionality

Figure 3-1

Figure 3-2

To facilitate such functionality, the

Array

object provides two methods,

push()

and

pop()

. As you

might expect, the

push()

method adds one or more items to the end of the

Array

whereas the

pop()

method removes the very last item (

length – 1

) from the array and returns it as the function value.

Consider the following example:

var stack = new Array;

stack.push(“red”);

stack.push(“green”);

stack.push(“yellow”);

alert(stack.toString()); //outputs “red,green,yellow”

var vItem = stack.pop();

alert(vItem); //outputs “yellow”

alert(stack.toString()); //outputs “red,green”

In the previous code, an empty

Array

object is created and then populated by using the

push()

method

numerous times (note that even though this example shows only one argument for the

push()

method,

you can, in fact, pass as many arguments as you wish). After the array is filled, the string value is output

(

“red,green,yellow”

) to assure that all items have been added. Then, the

pop()

method is called,

top

bottom

Pop off the stack

top

bottom

Push onto the stack

Chapter 3

06_579088 ch03.qxd 3/28/05 11:36 AM Page 74