<!DOCTYPE html>
<html>
<head>
<style>
.example {
color: red;
padding: 5px;
width: 150px;
font-size: 15px;
}
</style>
</head>
<body>
<p>Click the button to see how many attributes the button element has:</p>
<button onclick="myFunction()" class="example">Try it</button>
<p><strong>Note:</strong> In Internet Explorer 8 and earlier, the attributes property will return a collection of all possible attributes for the element, and will, in this example, display a much higher number than 1.</p>
<p>The result should be 2 (the button element's onclick and class attribute).</p>
<p id="demo"></p>
<script>
function myFunction() {
var x = document.getElementsByTagName("BUTTON")[0].attributes.length;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>