Html do names have to be unique

Does a name attribute have to be unique in a HTML document?

The name attribute is only valid on the and form elements ( , and ). It’s used to specify the name to associate with the name/value pair that is submitted on a form post.

if checked will submit foo=1 . In the DOM you can reference form elements from the form.elements collection by specifying the name as the index. If name is not unique, the collection returns an array of elements rather than the element. Modern DOM’s support looking up form elements by name as:

 document.getElementsByName(nameValue) 

note: it always returns an array even if only one element is found.

id attribute is from the XML world, and is a unique id for any node, not just form elements. Unlike the name attribute it is valid on any HTML node. Also like the name attribute, it must follow the valid identifier rules. The identifier should start with an alpha, and only contain alpha ( [a-zA-Z] ), numbers, hyphen, underscore and colons (note ASP.NET breaks this rule by starting reserved IDs with a underscore — thus they will always fail an HTML/XML lint — actually some proxies strip them). To find any HTML element by id you use:

document.getElementById(idvalue) 

this only returns one DOM node.

Solution 2

The name attribute is not unique. For instance, it is used to group radio buttons. It represents the value of a particular form property. id s must be unique.

Solution 3

ID should be unique but you can use multiple form elements with the same NAME. This is standard for how radio buttons work so you can force one seletion of a radio button group.

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Does a name attribute have to be unique in a HTML document?

Different elements may have same name though. In the DOM you can reference form elements from the collection by specifying the as the index.

Does a name attribute have to be unique in a HTML document?

I remember reading in the spec once that both the id attribute and the name attribute share the same namespace and have to be unique. Henceforth I’ve always tried to fulfill this requirement in my applications, dreading even to give the same id and name to the same element.

But lately I’ve started working with ASP.NET MVC 3, and it (like PHP) can use the same name attribute on several input controls to form a collection of values at server-side. I tried to look up the relevant section in the spec — but failed to find it. Perhaps I have misunderstood something then, or read the wrong documentation?

How is it then? I want to produce as valid HTML as possible (both 4.01 and 5 in different apps). Can I use this trick without fear? Or would I be violating something and should better stick to unique values?

The name attribute is only valid on the and form elements ( , and ). It’s used to specify the name to associate with the name/value pair that is submitted on a form post.

if checked will submit foo=1 . In the DOM you can reference form elements from the form.elements collection by specifying the name as the index. If name is not unique, the collection returns an array of elements rather than the element. Modern DOM’s support looking up form elements by name as:

 document.getElementsByName(nameValue) 

note: it always returns an array even if only one element is found.

id attribute is from the XML world, and is a unique id for any node, not just form elements. Unlike the name attribute it is valid on any HTML node. Also like the name attribute, it must follow the valid identifier rules. The identifier should start with an alpha, and only contain alpha ( [a-zA-Z] ), numbers, hyphen, underscore and colons (note ASP.NET breaks this rule by starting reserved IDs with a underscore — thus they will always fail an HTML/XML lint — actually some proxies strip them). To find any HTML element by id you use:

document.getElementById(idvalue) 

this only returns one DOM node.

The name attribute is not unique. For instance, it is used to group radio buttons. It represents the value of a particular form property. id s must be unique.

ID should be unique but you can use multiple form elements with the same NAME. This is standard for how radio buttons work so you can force one seletion of a radio button group.

Does a name attribute have to be unique in a HTML, id attribute is from the XML world, and is a unique id for any node, not just form elements. Unlike the name attribute it is valid on any HTML node. Also like the name attribute, it must follow the valid identifier rules. Usage exampledocument.getElementsByName(nameValue)Feedback

Is it redundant to use the «name» attribute for input fields in modern web development?

I’ve noticed a lot of websites with form(s) containing input fields whose «name» attribute is specified even if it isn’t used for styling or scripting purpose!

Moreover, according to the official document about the form in HTML document .

name = cdata [CI] This attribute names the element so that it may be referred to from style sheets or scripts. Note. This attribute has been included for backwards compatibility. Applications should use the id attribute to identify elements.

So, my question is: should this attribute used only for styling and scripting purposes?

EDIT: In particular, could be avoided the use of this attribute with input fields of «text» type (when there aren’t no styling or scripting purposes)?

EDIT 2: So, you have almost confirmed what I had thought about: the «name» attribute will be deprecated in further HTML specifications/standards. It is still «alive» only for backwards compatibility . in some cases can be avoided but there are still some cases (such as the radio button) where it is necessary!

I think you’ll find almost every site will have inputs with the name attribute. I don’t see it going away anytime soon.

The name attribute specifies a name for an input element.

The name attribute is used to identify form data after it has been submitted to the server, or to reference form data using JavaScript on the client side.

Note: Only form elements with a name attribute will have their values passed when submitting a form.

The name attribute is the notation to reference specific elements within the scope of a webpage through non-DOM Javascript:

document.forms['your_form'].elements['aa'] 

The id attribute for the element needs to be set with the same value for the following to work:

My understanding is that when Netscape created Javascript, it used the name attribute. The HTML spec however decided to go with id , but kept name for backwards compatibility. IME, using the name attribute was required for Internet Explorer 6 support because the javascript engine in IE wouldn’t read the id attribute — only the name though both were defined.

. could be avoided the use of this attribute with input fields of «text» type (when there aren’t no styling or scripting purposes)?

If you don’t have any javascript attached to the text fields, yes — they would be unnecessary.

There are differences between id and name attributes. An id is applicable to any element in the HTML document while a name is relevant for input fields only. An id is required by standard to be unique in a page (though not necessarily followed in all web pages). Different elements may have same name though. One particular case comes into mind is the radio button. All radio buttons should have the same name and the value of the one selected would be given back to the form. So you can see that name still has significance in HTML form processing.

I have seen in automatic HTML form generation systems (like zope.formlib), that id and name attributes both are automatically generated for different types of input widgets. Such automatic form generation systems take proper care of all the nuances associated with differences in id and name attributes. They also do things like generating a hidden input element for each checkbox element. So wherever possible, I try to use some sort of automatic HTML form generation mechanism and let it take care of the issues involved.

This is an old question, but it’s worth noting that many modern JS frameworks rely on the name attribute. In particular, jQuery’s serialize function:

For a form element’s value to be included in the serialized string, the element must have a name attribute.

If anything, name seems to be making a comeback.

It’s also worth noting that the name attribute is useful because it has slightly more «scope» than id . id must be unique within a page, but the same name can be used multiple times. This makes it useful when you have multiple forms on the same page, or when you want to reference a group of checkboxes, etc.

HTML name Attribute, Definition and Usage. The name attribute specifies a name for an HTML element. This name attribute can be used to reference the element in a JavaScript. For a

element, the name attribute is used as a reference when the data is submitted. For an element, the name attribute can be used to target a …

Does <label> for attribute has to be unique?

Can I have two labels with the same for value? Example:

The for attribute links a control to an input , there is, so far as I know, no limit to the number of elements that can link to one input , so long as the id of that input (or textarea , select , etc) is unique.

For example, in the following demo both label elements will trigger the change (check/uncheck) of the checkbox input element:

This can be useful for adding error messages (post-validation, for example) that explicitly link to, or otherwise identify, the element in which there’s an error, without overriding/replacing the pre-existing label for that element.

Unfortunately there is, so far as I’ve yet found , no reference or documentation that explicitly allows an input (or similar element) to linked to only one control; however MDN’s entry for does state that:

The ID of a labelable form-related element in the same document as the label element. The first such element in the document with an ID matching the value of the for attribute is the labeled control for this label element.

Was the name attribute really needed in html?, name is for form element names and is not required to be unique (in fact, sometimes you need to reuse the same name ). id is, as the name indicates, an identifier for an element and must be unique in the document as a whole.

HTML: Display:none does this allow multiple ID-Attributes with same name (when «hidden»)?

according to the HTML Standards ID-Attributes of any HTML Tag in a webpage have to be unique in the document!?

Does this rule also apply to HTML Tags that have been «disabled/hidden» by using: display:none?

Is this valid HTML or not. So the question is do «display:none»= hidden Elements also «count/matter» in regard to the rule only having unique ID-Attributes in a single webpage?

It’s not a valid markup. Validation does not take into account CSS styles applied to DOM elements.

There still has to be only one element per ID, regardless of whether it’s visible or not, whether it is behind the others in the z-stack, whether it is positioned outside the viewport etc.

Ids MUST be unique. to do otherwise is flirting with disaster!

Of course, as others have mentioned, it’s not valid markup. You also have to think about DOM selection here. document.getElementById() selects one element with a particular ID, regardless of its visibility/display within the document.

It doesn’t matter if they are hidden or not they are still in the document. Even if they are created dynamically they shouldn’t have the same ID. «it’s not a valid markup» — Developer Art

What’s the point of HTML forms `name` attribute?, name attribute is not completely redundant vis-à-vis id. As aforementioned, it useful with , but less known is that it can also be used with with any HTMLCollection, such as the children property of any DOM element.

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