An id on a <ul> tag assigns an identifier to the element.
The identifier must be unique across the page.
An id attribute on a <ul> element.
<ul id="artists">
<li>Vincent Van Gogh</li>
<li>Paul Cézanne</li>
<li>Claude Monet</li>
</ul>
The id attribute assigns an identifier to the <ul> element.
The id allows JavaScript to easily access the <ul> 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.
<ul 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 (.). |
A <ul> element with a unique id.
Clicking the button displays the number of list items inside the unordered list.
<ul id="myul">
<li>Vincent Van Gogh</li>
<li>Paul Cézanne</li>
<li>Claude Monet</li>
</ul>
<br />
<button onclick="show();">Show # artists</button>
<script>
let show = () => {
let element = document.getElementById("myul");
let count = element.getElementsByTagName("li").length;
alert("# Artists = " + count);
}
</script>
The id attribute assigns a unique identifier for the <ul>.
Clicking the button calls JavaScript which locates the <ul> through the id.
It then counts the number of <li> inside the <ul> and displays it in an alert box.
Here is when id support started for each browser:
 Chrome
|
1.0 | Sep 2008 |
 Firefox
|
1.0 | Sep 2002 |
 IE/Edge
|
1.0 | Aug 1995 |
 Opera
|
1.0 | Jan 2006 |
 Safari
|
1.0 | Jan 2003 |
Back to <ul>
