Examples
Lets now provide some examples using "robust" functions.
Example 1
The first is a simple summation notation example, where a function adds up all of the numbers that get passed into it:
function summation(){ for (i=0;i<summation.arguments.length;i++){ total+=summation.arguments[i] } //call the function summation(3,5,3,5,3,2,6)
Example 2- Robust Preload Image Script
By default, whenever we wish to preload images (for use with rollover effects, for example), we have to go through the tedious steps of first creating a new image object for each image, then, for each image object, specify the path to the image itself. Using the rebust function concept, we can create a function whereby the webmaster simply has to enter the names of the images he/she wishes to preload, and they automatically get preloaded:
var myimages=new Array() function preloadimages(){ for (i=0;i<preloadimages.arguments.length;i++){ myimages[i]=new Image() myimages[i].src=preloadimages.arguments[i] } }
A simple demonstration of the above in action would be:
<head> <script> preloadimages("firstimage.gif", "secondimage.gif", "thirdimage.gif") </script> </head>