How To Replace Css Class In Javascript

In this blog post, we will learn how to replace a CSS class in JavaScript. This can be useful when you want to change the styling of an element based on user interaction or other events.

Step 1: Select the HTML Element

To replace a CSS class, we first need to select the HTML element whose class we want to change. We can do this using either the getElementById, getElementsByClassName, or querySelector methods.

For example, if our HTML element has an ID of “my-element”:

    var element = document.getElementById('my-element');
    

Or, if our HTML element has a class name of “my-class”:

    var element = document.getElementsByClassName('my-class')[0];
    

You can also use the querySelector method:

    var element = document.querySelector('.my-class');
    

Step 2: Replace the CSS Class

Once we have selected the HTML element, we can replace its CSS class using the classList property and the replace method.

For example, let’s say we want to replace the existing class “current-class” with the new class “new-class”:

    element.classList.replace('current-class', 'new-class');
    

Alternative Method: Using className Property

An alternative way to replace a CSS class is by using the className property. However, this method is not recommended if the element has multiple classes, as it will override all existing classes.

Here’s an example of how to replace the CSS class using the className property:

    element.className = 'new-class';
    

Conclusion

In this blog post, we learned how to replace a CSS class in JavaScript by selecting the HTML element and using the classList property with the replace method. We also looked at an alternative way to replace a CSS class using the className property, but it’s not recommended for elements with multiple classes. With this knowledge, you can change the styling of your elements based on user interaction or events more effectively.