Why should one add ID to their HTML tags?

Question

A simple question: why should we add the id into our HTML tags if they work perfectly well without them? I know that one of their uses is being able to navigate

Answer 1

AFAIK, they are used to uniquely refer to a tag.And makes it easier for you to refer to the tag.

Answer 2

Well, in most cases id is used to do other things along side page navigation, which is very general. Some of the cute uses of id attribute are include

1. A reference for scripts,Selecting elements to apply scripts to,
2. A style sheet selector, selecting elements for styling
3. Named anchors for linking to, which is what u called page navigation i guess

So simply because in most cases you will want to do something to or with your content in any tag, its good to put an identifier, that is the id attribute.

Answer 3

They're most often used to uniquely identify elements for styling (CSS) and scripting (JavaScript et al) purposes.

But if you're asking about HTML and only HTML, then one example where declarative IDs are useful is associating a <label> with its <input>, <button> or <textarea> control via its for attribute:

<label for="ex">Example field:</label>
<input type="text" name="ex" id="ex">

Without assigning this attribute, activating the label does nothing, but when you pair both elements together using for and id, activating the label causes its control to gain focus.

The other way to associate a form label with its control is to contain it within the label:

<label>
Example field:
<input type="text" name="ex">
</label>

But this doesn't always suit the structure of a form or a page, so an ID reference is offered as an alternative.

Other circumstances where an id attribute serves a function are covered extensively in Alohci's answer.

Answer 4

The main reason I use ids for my HTML elements is the fact that their selection is faster, in Javascript with getElementById and in CSS as well, using the #id class.

Of course, I'm not saying this is always a good idea, especially in CSS, where having classes based on ids can cause a lot of redundancy, it's just one of the reasons

Answer 5

You can use IDs to acces your divs from javascript, CSS and jquery. If you don't use IDs it will be very difficult for you to interact with your HTML page from JS.

Answer 6

IDs are used for accessing your elements in CSS and JavaScript. Strictly speaking IDs should uniquely identify an element. You can also use class attributes to identify groups of elements.

The id attribute provides a unique identifier for an element within the document. It may be used by an a element to create a hyperlink to this particular element.

This identifier may also be used in CSS code as a hook that can be used for styling purposes, or by JavaScript code (via the Document Object Model, or DOM) to make changes or add behavior to the element by referencing its unique id.

see http://reference.sitepoint.com/html/core-attributes/id

for more info on class see here: http://reference.sitepoint.com/html/core-attributes/class