HTML <u> id Attribute

An id on a <u> tag assigns an identifier to the element.

The identifier must be unique across the page.



An id attribute on a <u> tag.

This text is underlined.

  <u id="u-id">This text is underlined</u>.

Using id

The id attribute assigns an identifier to the <u> element.

The id allows JavaScript to easily access the <u> element.

It is also used to point to a specific id selector in a style sheet.

Tip:  id is a global attribute that can be applied to any HTML element.


<u id="identifier" />



Value Description
identifier A unique alphanumeric string. The id value must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens (-), underscores (_), colons (:), and periods (.).

More Examples

A <u> element with a unique id.
Clicking the button displays the text in the <u> element.

This text is underlined.

  <u id="myu">This text is underlined</u>.
<br />
<button onclick="show();">Show underlined text</button>

  let show = () => {
     let element = document.getElementById("myu");
     alert("Text = " + element.innerHTML);

Code explanation

The id attribute assigns a unique identifier for the <u>.

Clicking the button calls JavaScript which locates the <u> using the id.

Finally, the content of the <u> element is displayed in an alert box.

Browser support

Here is when id support started for each browser:

1.0 Sep 2008
1.0 Sep 2002
1.0 Aug 1995
1.0 Jan 2006
1.0 Jan 2003

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Author: Jack Poorte
Published: Jun 20 2021
Last Reviewed: Sep 30 2023

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