The isId Property contains a boolean value that returns a true if the Element has an attribute type of ID, otherwise, it returns a false or undefined value. This Property is used for read-only.
Syntax:
attribute.isId Return Value: It returns a Boolean value i.e. true if the attribute type is ID, else it returns a false.
Example: In this example, we will use isId Property.
<!DOCTYPE html>
<html>
<head>
<title>
DOM isID property
</title>
</head>
<body>
<center>
<h1 style="color:green;">GeeksforGeeks</h1>
<h2> DOM isId Property</h2>
<button onclick="geeks()">Submit</button>
<p id="sudo"></p>
<script>
function geeks() {
let x = document.getElementById("sudo");
x.innerHTML = x.attributes[0].isId;
}
</script>
</center>
</body>
</html>
Output:

Supported Browser: No major browser support the DOM isID property.