a onclick event code example
Example 1: javascript onclick
document.getElementById("myBtn").addEventListener("click", function() {
alert("Hello World!");
});
Example 2: HTML button onclick
<!DOCTYPE html>
<html>
<head>
<title>Title of the document</title>
</head>
<body>
<p>There is a hidden message for you. Click to see it.</p>
<button onclick="myFunction()">Click me!</button>
<p id="demo"></p>
<script>
function myFunction() {
document.getElementById("demo").innerHTML = "Hello Dear Visitor!</br> We are happy that you've chosen our website to learn programming languages. We're sure you'll become one of the best programmers in your country. Good luck to you!";
}
</script>
</body>
</html>
Example 3: run a function when a button has the onclick
<script>
function myFunction() {
alert("ALERT THIS FUNCTION HAS RUNNED");
}
</script>
<button onclick="myFunction">click to run function</button>
Example 4: javascript button onclick
document.getElementById('button').onclick = function() {
alert("button was clicked");
};