An id on a <th> tag assigns an identifier to the table header.
The identifier must be unique across the page.
An id attribute on a <th> element.
Full name | |
---|---|
Denice | Hobermann |
Paulo | Cornell |
<style>
table.tb { width: 250px; border-collapse: collapse; }
.tb th, .tb td { border: solid 1px #777; padding: 5px; }
.tb th { background-color: lightblue; text-align: center; }
</style>
<table class="tb">
<tr>
<th id="fullname" colspan="2">Full name</th>
</tr>
<tr>
<td>Denice</td>
<td>Hobermann</td>
</tr>
<tr>
<td>Paulo</td>
<td>Cornell</td>
</tr>
</table>
The id attribute assigns an identifier to the <th> element.
The id allows JavaScript to easily access the <th> 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.
<th 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 <th> element with a unique id attribute.
Clicking the button displays the text in the table header cell.
Full name | |
---|---|
Denice | Hobermann |
Paulo | Cornell |
<style>
table.tb { width: 250px; border-collapse: collapse; }
.tb th, .tb td { border: solid 1px #777; padding: 5px; }
.tb th { background-color: lightblue; text-align: center; }
</style>
<table class="tb">
<tr>
<th id="myth" colspan="2">Full name</th>
</tr>
<tr>
<td>Denice</td>
<td>Hobermann</td>
</tr>
<tr>
<td>Paulo</td>
<td>Cornell</td>
</tr>
</table>
<br />
<button onclick="show();">Show th content</button>
<script>
let show = () => {
let element = document.getElementById("myth");
alert("Content = " + element.innerHTML);
}
</script>
The id attribute assigns a unique identifier for the <th>.
Clicking the button calls JavaScript which locates the <th> using the id.
Finally, the content of the <th> element is displayed 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 |
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