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

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一生所求 2020-11-28 11:53

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\

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抹茶落季 (楼主)

2020-11-28 12:22

The name attribute is only valid on the
and form elements (,</code> and <code><select></code>). It's used to specify the <code>name</code> to associate with the name/value pair that is submitted on a form post.</p> <p>For example:</p> <pre><code><input type="checkbox" name="foo" value="1" /> </code></pre> <p>if checked will submit <code>foo=1</code>. In the DOM you can reference form elements from the <code>form.elements</code> collection by specifying the <code>name</code> as the index. If <code>name</code> 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:</p> <pre><code> document.getElementsByName(nameValue) </code></pre> <p>note: it always returns an array even if only one element is found.</p> <p><code>id</code> attribute is from the XML world, and is a unique id for any node, not just form elements. Unlike the <code>name</code> attribute it is valid on any HTML node. Also like the <code>name</code> attribute, it must follow the valid identifier rules. The identifier should start with an alpha, and only contain alpha (<code>[a-zA-Z]</code>), 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). 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