Using JavaScript to change an element's background color via CSS

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1

Hey everyone! I’m trying to figure out how to change the background color of an HTML element using JavaScript. I know we can do this with CSS, but I need to make it happen dynamically with JS. Does anyone know the best way to go about this?

Here’s what I’ve tried so far:

function changeColor(elementId, newColor) {
  let targetElement = document.getElementById(elementId);
  targetElement.style.backgroundColor = newColor;
}

// Usage
changeColor('myDiv', 'blue');

This kind of works, but I’m wondering if there’s a better or more efficient way to do it. Maybe using classList or something? Any tips or tricks would be super helpful. Thanks in advance!

2

Your current approach is valid, but there’s another method worth considering. I’ve had success using the setAttribute() function, which can be more performant in certain scenarios. Here’s an example:

function changeBackgroundColor(elementId, color) {
document.getElementById(elementId).setAttribute(‘style’, background-color: ${color};);
}

This method directly sets the style attribute, which can be beneficial when dealing with multiple style changes simultaneously. It’s also quite straightforward and easy to read.

One caveat: this approach will overwrite any existing inline styles. If that’s a concern, you might want to stick with your original method or combine approaches based on your specific use case.

3

hey neo_stars, ur approach looks solid! another option is using classList.add() to apply a predefined CSS class. like this:

document.getElementById(‘myDiv’).classList.add(‘blue-bg’);

where .blue-bg {background-color: blue;} is in ur CSS. this can b cleaner if u have multiple style changes.

4

Your current method works fine, but there’s another approach worth considering. I’ve found that using CSS custom properties (variables) can be quite flexible. Here’s how I’ve implemented it:

function setColor(elementId, color) {
  document.documentElement.style.setProperty('--dynamic-bg', color);
  document.getElementById(elementId).style.backgroundColor = 'var(--dynamic-bg)';
}

This way, you can easily update multiple elements sharing the same variable. It’s also great for theming. Just make sure to define the custom property in your CSS:

:root {
  --dynamic-bg: initial;
}

I’ve used this method in several projects, and it’s proven to be quite scalable and maintainable.