Given an HTML document and the task is to change the style properties (CSS Properties) of an element dynamically with the help of JavaScript.
Approach: Using element.style Property
The element.style property is represented by the CSSStyleDeclaration object, which is returned via the style property.
- Select the element whose style properties need to be changed.
 - Use element.style property to set the style attribute of an element.
 - Set the properties either by using bracket notation or dash notation.
 
Example 1: This example changes the color and background color of the heading element.
html
<!DOCTYPE html><html>  
<body>    <h1 id="h1" style="color:green;">        neveropen    </h1>  
    <p>        Click on the button to change         the style attribute    </p>  
    <button onclick="gfg_Run()">        Click here    </button>  
    <p id="result"></p>  
    <script>        let res = document.getElementById("result");        let heading = document.getElementById("h1");  
        function gfg_Run() {            heading.style["background-color"] = "green";            heading.style["color"] = "white";            res.innerHTML = "Style Attribute Changed";        }            </script></body>  
</html> | 
Output
How to change style attribute of an element dynamically using JavaScript ?
Example 2: This example changes the color, background color, and width properties of elements.Â
html
<!DOCTYPE html><html>  
<body>    <h1 id="h1" style="color:green;">        neveropen    </h1>  
    <p id="para">        Click on the button to change         the style attribute    </p>  
    <button onclick="gfg_Run()">        Click here    </button>  
    <p id="result"></p>  
    <script>        let heading = document.getElementById("h1");        let para = document.getElementById("para");        let res = document.getElementById("result");  
        function gfg_Run() {            heading.style["color"] = "white";            heading.style["background-color"] = "green";            heading.style["width"] = "300px";            heading.style["border"] = "1px solid black";  
            para.style["background-color"] = "green";            para.style["width"] = "400px";            para.style["border"] = "1px solid black";  
            res.innerHTML = "Style Attribute Changed";        }            </script></body>  
</html> | 
Output:
How to change style attribute of an element dynamically using JavaScript ?
