in javascript built in function like click function code example
Example 1: javascript onclick
document.getElementById("myBtn").addEventListener("click", function() {
alert("Hello World!");
});
Example 2: javascript click event
<button onclick="myFunction()">Click me</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML = "Hello World";
}
</script>