What is the difference between the id and name attributes? They both seem to serve the same purpose of providing an identifier.
I would like to know (specifically with regards to HTML forms) whether or not using both is necessary or encouraged for any reasons.
The name attribute is used when sending data in a form submission. Different controls respond differently. For example, you may have several radio buttons with different id attributes, but the same name. When submitted, there is just the one value in the response - the radio button you selected.
Of course, there's more to it than that, but it will definitely get you thinking in the right direction.
Use name attributes for form controls (such as <input> and <select>), as that's the identifier used in the POST or GET call that happens on form submission.
Use id attributes whenever you need to address a particular HTML element with CSS, JavaScript or a fragment identifier. It's possible to look up elements by name, too, but it's simpler and more reliable to look them up by ID.
name and id at all. The identifier uniquely identifies a particular HTML element on the page. The name attribute of an HTML form element, by contrast, does not have to be unique, and often isn't, such as with radio buttons or pages with multiple <form> elements. It is traditional to use the same string for name and id where both are used on a single HTML element, but nothing makes you do this.
Here is a brief summary:
id is used to identify the HTML element through the Document Object Model (via JavaScript or styled with CSS). id is expected to be unique within the page.
name corresponds to the form element and identifies what is posted back to the server.
The way I think about it and use it is simple:
id is used for CSS and JavaScript/jQuery (it has to be unique on a page).
name is used for form handling on the server when a form is submitted via HTML (it has to be unique in a form - to some extent, see Paul's comment below).
See id= vs name=:
What’s the difference? The short answer is, use both and don’t worry about it. But if you want to understand this goofiness, here’s the skinny: id= is for use as a target like this:
name= is also used to label the fields in the message send to a server with an HTTP (HyperText Transfer Protocol) GET or POST when you hit submit in a form. id= labels the fields for use by JavaScript and Java DOM (Document Object Model). The names in name= must be unique within a form. The names in id= must be unique within the entire document. Sometimes the name= and id= names will differ, because the server is expecting the same name from various forms in the same document or various radio buttons in the same form as in the example above. The id= must be unique; the name= must not be. JavaScript needed unique names, but there were too many documents already out here without unique name= names, so the W3 people invented the id tag that was required to be unique. Unfortunately older browsers did not understand it. So you need both naming schemes in your forms.
Note: attribute "name" for some tags like <a> is not supported in HTML5.
name is important for <input> tags in a <form> submission as the parameters are used in the HTTP, and id is merely a unique identifier
The ID tag - used by CSS, define a unique instance of a div, span or other elements. Appears within the JavaScript DOM model, allowing you to access them with various function calls.
The Name tag for fields - this is unique per form -- unless you are doing an array which you want to pass to PHP/server-side processing. You can access it via JavaScript by name, but I think that it does not appear as a node in the DOM or some restrictions may apply (you cannot use .innerHTML, for example, if I recall correctly).
Generally, it is assumed that name is always superseded by id. This is true, to some extent, but not for form fields and frame names, practically speaking. For example, with form elements, the name attribute is used to determine the name-value pairs to be sent to a server-side program and should not be eliminated. Browsers do not use id in that manner. To be on the safe side, you could use the name and id attributes on form elements. So, we would write the following:
<form id="myForm" name="myForm">
<input type="text" id="userName" name="userName" />
</form>
To ensure compatibility, having matching name and id attribute values when both are defined is a good idea. However, be careful—some tags, particularly radio buttons, must have nonunique name values, but require unique id values.
Once again, this should reference that id is not simply a replacement for name; they are different in purpose. Furthermore, do not discount the old-style approach, a deep look at modern libraries shows such syntax style used for performance and ease purposes at times. Your goal should always be in favor of compatibility.
Now in most elements, the name attribute has been deprecated in favor of the more ubiquitous id attribute. However, in some cases, particularly form fields (<button>, <input>, <select>, and <textarea>), the name attribute lives on, because it continues to be required to set the name-value pair for form submission. Also, we find that some elements, notably frames and links, may continue to use the name attribute, because it is often useful for retrieving these elements by name.
There is a clear distinction between id and name. Very often when name continues on, we can set the values the same. However, id must be unique, and name in some cases shouldn’t—think radio buttons. Sadly, the uniqueness of id values, while caught by markup validation, is not as consistent as it should be. CSS implementation in browsers will style objects that share an id value; thus, we may not catch markup or style errors that could affect our JavaScript until runtime.
This is taken from the book JavaScript - The Complete Reference by Thomas-Powell.
name should be the same (the server-side code doesn't care which was submitted), but the id must be different (because it must be unique within the whole page).
<form action="demo_form.asp">
<label for="male">Male</label>
<input type="radio" name="sex" id="male" value="male"><br>
<label for="female">Female</label>
<input type="radio" name="sex" id="female" value="female"><br>
<input type="submit" value="Submit">
</form>
The forum thread below has answers to the same basic question, but basically, id is used for scripting identification and name is for server-side.
id vs. name attribute for HTML controls
name is deprecated for link targets, and invalid in HTML5. It no longer works at least in the latest Firefox (v13). Change <a name="hello"> to <a id="hello">.
The target does not need to be an <a> tag. It can be <p id="hello"> or <h2 id="hello">, etc. which is often cleaner code.
As other posts say clearly, name is still used (needed) in forms. It is also still used in META tags.
a tag name attribute is deprecated, it is still supported by browsers including Firefox, so the answer is incorrect. Yes, for an anchor (target location) you should now use id on the element (<h2 id="hello">), but this wasn't really what the OP was asking.
name vs. id
name
Name of the element. For example used by the server to identify the fields in form submits.
Supporting elements are
idis what your frontend (CSS, JS) works with, whilenameis what your server receives and can then process. This is basically what Greeso's answer says.