JavaScript: Array Objects - Pop() and Lock
(Page 3 of 5 )
If you have read any of my other articles on methods and functions for other languages, then you will know that JavaScript shares many of them. For instance, I just wrote an article on Perl that uses the pop(), push(), shift(), unshift(), and splice methods (to name a few), which have the same use in Perl as they do in JavaScript.
As our table indicated earlier, we use pop() when we want to remove and return the right most (or end) element in an array. Here is the code:
<html>
<body>
<script type="text/javascript">
var bboys = new Array(3);
bboys[0] = "Greg";
bboys[1] = "Bobby";
bboys[2] = "Peter";
document.write(bboys + "<br />");
document.write(bboys.pop() + "<br />");
document.write(bboys);
</script>
</body>
</html>
This code is pretty self-explanatory. First we assign the bboys array some values. Then we write out the values to the screen, and remove the end element from the array using pop(), printing out the removed element. Finally, we print out the values of bboys once more to show that “Peter” has been removed.
Here is the result:
Greg,Bobby,Peter
Peter
Greg,Bobby
Note that we could keep popping the array until it was empty:
<html>
<body>
<script type="text/javascript">
var bboys = new Array(3);
bboys[0] = "Greg";
bboys[1] = "Bobby";
bboys[2] = "Peter";
document.write(bboys + "<br />");
document.write(bboys.pop() + "<br />");
document.write(bboys.pop() + "<br />");
document.write(bboys.pop() + "<br />");
document.write(bboys);
</script>
</body>
</html>
Each time we pop() the array, the last element gets removed until there are no values left in the array. Here is how it prints out (note that the final document.write prints nothing, as nothing remains to be printed):
Greg,Bobby,Peter
Peter
Bobby
Greg
Next: Using Pop() to Assign a Value to a Variable >>
More JavaScript Articles
More By James Payne
/ 5 
