ArticleZip > How Do You Read Css Rule Values With Javascript

How Do You Read Css Rule Values With Javascript

Have you ever wondered how you can read CSS rule values with JavaScript? It's a common need when you're working on web projects and want to manipulate styles dynamically. Luckily, JavaScript provides us with the tools to access these values effortlessly.

One way to read CSS rule values with JavaScript is by using the `getComputedStyle` method. This method allows you to get the computed style of an element, which includes all styles applied to that element, even those inherited from stylesheets or inline styles.

Here's a simple example to demonstrate how you can use `getComputedStyle` to read CSS rule values:

Html

.myElement {
      color: red;
      font-size: 16px;
    }
  


  <div class="myElement">Hello, world!</div>

  
    const element = document.querySelector('.myElement');
    const styles = window.getComputedStyle(element);

    const color = styles.getPropertyValue('color');
    const fontSize = styles.getPropertyValue('font-size');

    console.log(color); // Output: "rgb(255, 0, 0)"
    console.log(fontSize); // Output: "16px"

In this example, we first select an element with the class `myElement`. We then use `window.getComputedStyle` to get the computed styles of that element. By calling `getPropertyValue` on the styles object and passing the CSS property name as an argument, we can retrieve the value of that property.

You can also read individual CSS properties directly from the style object of an element. This allows you to access inline styles applied directly to an element.

Here's how you can read CSS rule values using the `style` object:

Html

.myElement {
      color: blue;
    }
  


  <div class="myElement" style="font-size: 20px">Hello, world!</div>

  
    const element = document.querySelector('.myElement');

    const color = element.style.color;
    const fontSize = element.style.fontSize;

    console.log(color); // Output: "blue"
    console.log(fontSize); // Output: "20px"

In this example, we select an element with the class `myElement` and then directly access the `style` object of that element to read the color and font-size properties.

By leveraging these methods in JavaScript, you can easily read CSS rule values from your HTML elements and use them to create dynamic and interactive web experiences. So next time you need to access style information in your projects, remember these handy techniques!

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