Native JavaScript Utility Patterns

Quick Guide: Most utility-library calls now have a native equivalent with no bundle cost. The four that change how code is written are structuredClone for deep copies, the ES2023 immutable array methods (toSorted, toReversed, toSpliced, with), Object.groupBy / Map.groupBy, and the ES2025 Set operations. The two facts that catch people out: a structured clone drops prototypes and throws on functions, and the immutable array methods copy one level deep.

Detailed Resources:

• examples/core.md — cloning, immutable updates, negative indexing, searching from the end
• examples/arrays.md — deduplication, set operations, grouping, chunking, sorting, compacting
• examples/objects.md — typed pick/omit/mapValues, deep merge, lookup maps, freezing
• reference.md — lodash-to-native table, function utilities (debounce, throttle, memoize), availability

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