DOM Rendering Performance

Batching reads then writes provides better rendering performance because: 1) It allows the browser to optimize layout calculations by avoiding forced synchronous layouts, 2) Reduces the number of reflow/repaint cycles, 3) Prevents layout thrashing by separating read and write operations, 4) Enables the browser to batch similar operations together. Best practices include: - First perform all DOM reads (offsetWidth, clientHeight, etc.) - Store necessary values in variables - Then perform all DOM writes (style changes, classList updates, etc.) - Use requestAnimationFrame for visual updates This pattern is particularly important in loops or when manipulating multiple elements.