How Can I Dynamically Modify CSS Class Definitions?

Dynamic Modification of CSS Class Definitions

Changing CSS class definitions on the fly can be an essential feature for dynamic web applications. While adding new classes can be easily accomplished, modifying or removing existing definitions poses a different challenge.

Modifying CSS Class Rules

To change the font-size rule for the ".menu" class:

// Get the stylesheet index
const sheetIndex = document.styleSheets.length - 1;

// Get the CSS rule object
const rule = document.styleSheets[sheetIndex].cssRules[0];

// Set the new font size
rule.style.setProperty('font-size', '10px', null);

This will update the font size for all elements using the ".menu" class.

Removing CSS Class Definitions

To remove the ".menu" class definition entirely:

// Get the stylesheet index
const sheetIndex = document.styleSheets.length - 1;

// Remove the rule from the stylesheet
document.styleSheets[sheetIndex].deleteRule(0);

This will remove the ".menu" class definition from the stylesheet, causing all elements using it to lose those styling attributes.

Note: It's important to keep in mind browser compatibility when using these techniques, as not all browsers support the full range of CSS manipulation capabilities.

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