Difference Between Id and Name Attributes in Html

Difference between id and name attributes in HTML

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.

Difference between id and name attributes in HTML form

The difference between name and id:

id is used to identify the HTML element in the page. id is expected to be unique within the page.

name corresponds to the form element and identifies what is posted back to the server.

using both is necessary or encouraged for any reasons? it's not necessary, for form element just name is enough but if you want to do some CSS or JS operations, doing it on the element with id is much more easier.

If using both together, should they use the same? no, they aren't related to each other.

Name vs Id attribute in HTML

Here are some differences between both:

name has never been a div element attribute.
name as used on the form controls (input, textarea, select, and button elements) is radically different from the id attribute on named elements. In this case, the name attribute relates to how data is labeled when sent to server, and multiple elements may share the same name.
The id attribute on the other hand is for identifying one unique element for the purposes of scripting, styling, or addressing.
The use of the name attribute on other elements than form controls was in HTML 4.01 the same as that of id, but it allowed for a wider set of characters than the id attribute and wasn't controlled in quite the same way. Because of this ambiguity the W3C decided to deprecate/remove the name attribute on those elements in favor for the unambigous id attribute in XHTML.
This is also connected to another detail of XML however - only one attribute of any element may be of the type ID, which would not be the case if they let name stay on the element, but corrected the ambiguity problems.
As the name attribute didn't work the same on those two sets of elements, it was best to remove one of them.

In short, for backwards compatibility, you should use the name and id attribute both, both set to the same value, for all elements except form controls if you use HTML 4.01 or XHTML 1.0 Transitional. If you use XHTML 1.0 Strict or later you should use only id. For form controls, you should use name for what you want the form to send to the server and for DOM 0 access, and only use id for styling, DOM1-3 access or addressing reasons

What is difference between for, name and id?

The for= attribute in the label is used to link the label to one specific input on the page.

Since name= is not unique for inputs (I can have multiple inputs with the same name), the for= element on the label links to an id= attribute on the input.

The name attribute is used to determine under what name to submit the input.

HTML: Can always the same identifier be used for name and id attributes?

Is there any reason to choose different identifiers for the name and id attributes?

Yes. IDs must be unique, names don't have to be. Names must be the same for members of a radio group, so they can't all have the same id—well, they can in practice but accessing the elements by ID will be problematic. And if you don't access them by ID, why have it?

Are there any use-cases for which different identifiers are required?

Yes, radio buttons. Only one can have an id that is the same as its name. But otherwise, there are few restrictions, such as than never give form controls the name or id of a method or property of the form itself, like "submit", as it will mask the same–named property of the form.

Also, names "_charset_" and "isindex" are special.

Are there any differences in syntax? (for example you can use "myarray[123]" for the name attribute and PHP will understand that correctly and create an array, can that also be used in a similar manner for id-attributes in Javascript or CSS - and if not, is that a syntax-error or is it simply a valid identifier with brackets in it?)

Yes. The rules for name and id attribute values are similar but an ID must not contain spaces (and some values for name are special, see above). There were more restrictions on id attributes in HTML4 (e.g. ids couldn't start with a number), but in practice they weren't implemented in browsers.

Some characters that are valid in names and ids must be quoted to use as CSS selectors, e.g. for:

<div id="d[]">

the CSS selector is:

#d\[\]

and for use with the Selectors API:

#d\\[\\]

(e.g. document.querySelector('#d\\[\\]').

Are both case-sensitive?

Yes.

HTML 5 difference input id and input name?

In short, the name is the identifier that is sent to the server when you submit the form. The id is a unique identifier for the browser, clientside, for javascript and such.

exact difference between name and value attribute in input tag

actually, the value is the property that defines the input data while the name property defines the input field name that can be used for form handling in backend languages like PHP, ...

the name should be unique (in some cases it can be an array of names like multiple checkboxes use case) while the value can be dynamic and repeatable for all inputs.