Universal Selector: Performance Implications
The use of the universal selector (*) in CSS has been a point of performance concern, particularly for websites with high page views. Let's examine the performance implications of this selector.
As you've noted in your example, the universal selector can be used to apply styles to all elements in a document. It essentially replaces the need for explicitly specifying each element in a rule set.
In earlier versions of browsers, the universal selector was indeed slower due to its overhead in matching against all elements on the page. However, in modern browsers, the performance impact has been significantly reduced.
Negligible Impact in Modern Browsers
Benchmarks indicate that the performance impact of using the universal selector is negligible. As long as you're not applying performance-intensive effects like box shadows or 3D transformations to every element, the universal selector performs comparably to a list of explicit element selectors.
Myth vs. Reality
The myth that the universal selector is inherently slow likely stems from its early implementation in browsers. However, modern browsers have optimized their engines to minimize the performance hit associated with this selector.
Best Practices
If you're primarily concerned with concise CSS, you can opt for using the universal selector. However, if you anticipate applying slow-acting effects to most elements, it's better to use explicit selectors to avoid unnecessary performance overhead.
Conclusion
In conclusion, while the universal selector was once a performance concern, it is no longer a significant issue in modern browsers. The performance impact is negligible unless you're applying performance-intensive effects to a substantial number of elements. If you prioritize conciseness, you can confidently use the universal selector without compromising performance.
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