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DOM Tree Walk 3: Basic Selector Engine (Hard)

By FrontendAtlas Team · Updated Jan 31, 2026

Implement a small selector engine: queryAll(root, selector) that returns all matching nodes in document order from a DOM-like tree. This is a classic "build a tiny querySelectorAll" interview task. DOM-like node shape: - nodeType: 1 for element, 3 for text - tagName: string for elements…

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DOM Tree Walk 3: Basic Selector Engine (Hard): Implement a small selector engine: queryAll(root, selector) that returns all matching nodes in document order from a DOM-like tree. This is a classic "build…. Expect dom and tree decisions under hard level constraints.

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