November 19, 2000 - Counting Elements in a Document | WebReference

November 19, 2000 - Counting Elements in a Document

Yehuda Shiran November 19, 2000
Counting Elements in a Document
Tips: November 2000

Yehuda Shiran, Ph.D.
Doc JavaScript

Suppose you need to know how many DIV elements there are on the page. In Netscape Navigator, the number of layers is document.layers.length. It is not that trivial in Internet Explorer.

You need to use the tags method of the document.all array. The tags() method retrieves all HTML elements of a particular tag from the document.all array. It returns an array of elements. The following line will populate the given array with all DIV elements:

var divArray = document.all.tags("DIV");
To find the total number of DIV elements, just use divArrary.length. For example, click this link from within Internet Explorer to compute and echo the number of FONT elements in this tip. We just put the following line in the JavaScript section at the top of this page:

var divArray = document.all.tags("FONT");
And the link above is assembled as:

<A HREF="javascript:alert('The number of FONT elements in this 
tip is ' + divArray.length)">compute and echo</A>