push() and pop():Array Stack Methods

An array can act just like a stack. A stack is a last-in-first-out (LIFO) structure.

The insertion (called a push) and removal (called a pop) in a stack occur at the top of the stack. The push() method accepts any number of arguments and adds them to the end of the array returning the array's new length.

The pop() method removes the last item in the array, decrements the array's length, and returns that item.

 
<!DOCTYPE html>
<html>
<head>
    <title>Example</title>
    <script type="text/javascript">
        var colors = new Array(); //create an array 
        var count = colors.push("A", "B"); //push two items 
        document.writeln(count); //2 
        count = colors.push("C"); //push another item on 
        document.writeln(count); //3 
        var item = colors.pop(); //get the last item 
        document.writeln(item); //"C" 
        document.writeln(colors.length); //2 
        
       
    </script>
</head>
<body>
</body>
</html>

Click to view the demo

The following code uses both push and index to add data to an array:

 
<!DOCTYPE html>
<html>
<head>
    <title>Example</title>
    <script type="text/javascript">
        var colors = ["A", "B"]; 
        colors.push("C"); //add another item 
        colors[3] = "D"; //add an item 
        document.writeln(colors.length); //4 
        
        var item = colors.pop(); //get the last item 
        document.writeln(item); //"D" 
       
    </script>
</head>
<body>
</body>
</html>

Click to view the demo