An id on a <form> tag assigns an identifier to the form.
The identifier must be unique across the page.
<form id="vehicle-form" action="/tutorial/action.html">
<fieldset>
<legend>Vehicle Details</legend>
<input type="text" placeholder="Make" name="make"><br /><br />
<input type="text" placeholder="Model" name="model"><br /><br />
<input type="text" placeholder="Age" name="age"><br /><br />
<button type="submit">Submit</button>
</fieldset>
</form>
The id attribute assigns an identifier to the <form> element.
The id allows JavaScript to easily access the <form> 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.
<form id="identifier" />
| Value | Description |
|---|---|
| identifier | A unique alphanumeric string. The id value must begin with a letter ([aside-Zaside-z]) and may be followed by any number of letters, digits ([0-9]), hyphens (-), underscores (_), colons (:), and periods (.). |
A <form> with a unique id.
Clicking the button displays the value of the form's action attribute.
<form id="myform" action="/tutorial/action.html">
<input type="text" name="firstname" placeholder="First Name">
<input type="text" name="lastname" placeholder="Last Name">
<button type="submit">Submit</button>
</form>
<br/>
<button onclick="show();">Show form action</button>
<script>
let show = () => {
let element = document.getElementById("myform");
alert("Action = " + element.getAttribute('action'));
}
</script>
The id attribute assigns a unique identifier for the <form> element.
Clicking the button calls JavaScript which locates the <form> using the id.
Finally, the action value of the <form> 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 |
Back to <form>
