JavaScript – Change the Top Border of HTML Element

To change the top border of a HTML Element using JavaScript, get reference to this HTML element, and assign required value to the element.style.borderTop property.

In the following example, we will change the top border of HTML Element with id "myElement" to "2px dotted red", in JavaScript, using element.style.borderTop property.

Example

<!DOCTYPE html>
<html lang="en">
<head>
    <style>
        #myElement {
            border:1px solid #CCC;
            width:100px;
            height:100px;
        }
    </style>
    <meta charset="utf-8">
</head> 
<body>
    <h2>Change Top Border of HTML Element in JavaScript</h2>
    <div id="myElement">Hello World!</div>
    <br>
    <button type="button" onclick="changeStyle()">Click Me</button>
    <script>
    function changeStyle(){
        var element = document.getElementById("myElement");
        element.style.borderTop = "2px dotted red";;
    }
    </script>
</body>
</html>
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Conclusion

In this JavaScript Tutorial, we learned how to change the top border of a HTML Element using JavaScript.