html js button onclick 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 onclick

document.getElementById("Save").onclick = function ()
    {
     alert("hello");
     //validation code to see State field is mandatory.  
    }

Example 5: javascript onclick button

var button = document.querySelector('button');
button.onclick = function() {
  //do stuff
}

Example 6: html js button onclick

// In HTML:
// <button id="buttonID" onclick="yourJSFunction()">Text</button>

// In JavaScript:
function yourJSFunction() {
  // Do stuff
 }