You could have a single dimensional array from 0 to 9 that lists the major planets in the solar system.  You could then augment this to a two dimensional array by associating each planet with its major orbiting moons.  You could then augment this even more to a third dimension by considering the orbiting artificial satellites.  In the end, all of the items in this array are text for names.  The numbering scheme would need to be specified, but hopefully you already have enough experience with arrays so that I don't need to talk about this more.

Because of the nature of arrays it is common to use loops to work with them.  This is one of the main reasons that Thau! has put them together in a chapter.  We have now talked about loops, now we will talk more about arrays.  We will start with some of the built-in arrays that JavaScript uses to interact with webpages.  The main one I want to work with is the array that contains all the images in a page.

First you need to copy these images.

window.document.write("<center><li><font size=4 color='0000aa'><b>" + window.document.images[i].name + "</b></font></center>");

}

window.document.write("</ul>");

</script>

</body>
</html>

• displays the images in a table
• counts the images
• lists them out

The code associated with displaying the number of images and their names is

<script language="JavaScript">
var number_images = window.document.images.length;

window.document.write("<center><P><font size=4 color='990099'><b>There are " + number_images + " images on this page.</b></font></P></center>");
window.document.write("<center><BR><font size=5 color='0000aa'><b>Their names are:</b></font></center><ul>");

for( var i=0; i < number_images; i++)
{

window.document.write("<center><li><font size=4 color='0000aa'><b>" + window.document.images[i].name + "</b></font></center>");

}

window.document.write("</ul>");

</script>

The first section gets the number_images and then uses window.document.write commands to display them.  The loop displays the name making use of the name properties of the images array.  In order for this to work, the images must all have assigned name="someName" in the HTML tag for the image.