The id attribute on n <table> tag assigns an identifier to the table.
The identifier must be unique across the page.
An id attribute on n <table> element.
| First name | Last name |
|---|---|
| Denice | Hobermann |
| Paulo | Cornell |
| Jane | Hollander |
<style>
table.tb { border-collapse: collapse; width:300px; }
.tb th, .tb td { padding: 5px; border: solid 1px #777; }
.tb th { background-color: lightblue;}
</style>
<table class="tb" id="members">
<tr>
<th>First name</th>
<th>Last name</th>
</tr>
<tr>
<td>Denice</td>
<td>Hobermann</td>
</tr>
<tr>
<td>Paulo</td>
<td>Cornell</td>
</tr>
<tr>
<td>Jane</td>
<td>Hollander</td>
</tr>
</table>
The id attribute assigns an identifier to the <table> element.
The id allows JavaScript to easily access the <table> 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.
<table 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 <table> element with a unique id attribute.
Clicking the button displays the number of rows in the table -- both header and data rows.
| First name | Last name |
|---|---|
| Denice | Hobermann |
| Paulo | Cornell |
| Jane | Hollander |
<style>
table.tb { border-collapse: collapse; width:300px; }
.tb th, .tb td { padding: 5px; border: solid 1px #777; }
.tb th { background-color: lightblue;}
</style>
<table class="tb" id="mytable">
<tr>
<th>First name</th>
<th>Last name</th>
</tr>
<tr>
<td>Denice</td>
<td>Hobermann</td>
</tr>
<tr>
<td>Paulo</td>
<td>Cornell</td>
</tr>
<tr>
<td>Jane</td>
<td>Hollander</td>
</tr>
</table>
<br />
<button onclick="show();">Show # rows</button>
<script>
let show = () => {
let element = document.getElementById("mytable");
let length = element.getElementsByTagName("tr").length;
alert("# Rows = " + length);
}
</script>
The id attribute assigns a unique identifier for the <table>.
Clicking the button calls JavaScript which locates the <table> using the id.
It then counts the number of <tr> (table row) inside the <table> 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 <table>
