How to call a JavaScript Function from an onmouseover Event ?

Last Updated : 15 Apr, 2024

The onmouseover event in JavaScript is triggered when the mouse pointer moves onto an element, such as a button, image, or text. We will see how to call JavaScript function from an onmouseover event in various ways, like using the onmouseover Attribute and Using Event Listener.

Table of Content

Using onmouseover attribute
Using Event Listener

Using the onmouseover Attribute

In this approach, we are directly adding the onmouseover attribute to an HTML element. The HTML button element utilizes the onmouseover attribute to trigger the JavaScript function greet() when the mouse hovers over it. Upon hovering, an alert message “Welcome to GeeksForGeeks!” displays the onmouseover event’s usage to call a function.

Example: The below example uses the onmouseover attribute to call a JavaScript function from an onmouseover Event

HTML

<!DOCTYPE html>
<html>

<head>
    <title>Call Function on Mouseover</title>
    <style>
        body {
            text-align: center;
        }

        h1 {
            color: green;
        }
    </style>
</head>

<body>
    <h1>GeeksForGeeks</h1>
    <h3>
          Call Function on mouseover using
          onmouseover attribute
      </h3>

    <button id="myButton" onmouseover="greet()">
          Hover over me
      </button>

    <script>
        function greet() {
            alert('Welcome to GeeksForGeeks!');
        }
    </script>
</body>

</html>

Output:

Using Event Listener

In this approach, we utilize the addEventListener method to bind an event listener to an HTML element. The JavaScript function changeText() is linked to the HTML button element using the addEventListener method, activating when the mouse hovers over it. Upon hover, the text within the paragraph element with the ID “myParagraph” is dynamically altered to “This is a New text!”.

Example: The below example uses the addEventListener method to call a JavaScript function from an onmouseover Event.

HTML

<!DOCTYPE html>
<html>

<head>
    <style>
        body {
            text-align: center;
        }

        h1 {
            color: green;
        }
    </style>
</head>

<body>
    <h1>GeeksForGeeks</h1>
    <h3>
          Call Function on mouseover 
          using Event Listener
      </h3>
    <button id="myButton">Hover over me</button>
    <p id="myParagraph">Original text</p>

    <script>

        // Function to change text on mouseover
        function changeText() {
            var paragraph = 
                document.getElementById('myParagraph');
            paragraph.textContent = 'This is a New text!';
        }

        document.addEventListener('DOMContentLoaded',
                                      function () {

            // Select the button element
            var button = document.getElementById('myButton');

            // Attach event listener for the 'mouseover' event
            button.addEventListener('mouseover', changeText);
        });
    </script>
</body>

</html>