Building a Drop-Down Menu with Nested HTML Lists

Introduction

Undoubtedly, HTML lists are an important piece within the structure of many web sites. They allow you to display bulleted information in an elegant, well-categorized manner. However, the traditional usage of lists can be extended by nesting their elements as many times as needed, in this way making it possible to build useful web page elements, such as hierarchical navigation menus, to cite an illustrative example.

If you're interested in learning how to use nested HTML lists for building different kinds of hierarchical web-based user interfaces, then you should take a close look at this series of articles, since it'll teach you the key concepts that surround the creation of nested lists, and also show you how to employ them in production environments.

Naturally, if you've already read all of the previous articles of this series, then you're probably familiar with nesting HTML lists and using them to create well-structured sets of bulleted items. Speaking more specifically, in the preceding tutorial I explained how to utilize a basic nested list for building a hierarchical links bar, commonly seen nowadays on many web sites.

Since it's relatively easy to develop a navigation mechanism like the one mentioned above, in this final installment of the series, I'm going to discuss how to use nested lists for constructing a standard drop-down menu. Hopefully, this process will be pretty straightforward for you; it'll only require a basic background in CSS and JavaScript, since a bit of client-side scripting will be used for addressing some specific incompatibilities inherent to Internet Explorer 6 and below.

Having outlined the topic that will be treated in this last part of the series, it's time to leave all the preliminaries behind and start learning how to use nested HTML lists to develop a neat drop-down menu. Let's begin now!