What are event handlers in JavaScript?

JavascriptWeb DevelopmentFront End Technology

JavaScript's interaction with HTML is handled through events that occur when the user or the browser manipulates a page.

When the page loads, it is called an event. When the user clicks a button, that click to is an event. Other examples include events like pressing any key, closing a window, resizing a window, etc.

Here are some examples:

onclick Event Type

This is the most frequently used event type, which occurs when a user clicks the left button of his mouse. You can put your validation, warning etc., against this event type.

Try the following example.

Live Demo

<html>
   <head>
      <script>
         <!--
            function sayHello() {
               alert("Hello World")
            }
         //-->
      </script>
   </head>
   <body>
      <p>Click the following button and see result</p>
      <form>
         <input type="button" onclick="sayHello()" value="Say Hello" />
      </form>
   </body>
</html>

 onmouseover and onmouseout

These two event types will help you create nice effects with images or even with text as well. The onmouseover event triggers when you bring your mouse over any element and the onmouseout triggers when you move your mouse out from that element. Try the following example.

Live Demo

<html>
   <head>
      <script>
         <!--
            function over() {
               document.write ("Mouse Over");
            }
            function out() {
               document.write ("Mouse Out");
            }
         //-->
      </script>
   </head>
   <body>
      <p>Bring your mouse inside the division to see the result:</p>
      <div onmouseover="over()" onmouseout="out()">
         <h2> This is inside the division </h2>
      </div>
   </body>
</html>
raja
Published on 30-Jan-2018 10:27:56
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