JavaScript Snippet

Deep Structural Equality Check

Difficulty: Hard

Comparing two values structurally is a deceptively hard problem: `===` only checks reference, `JSON.stringify` reorders keys and drops undefined, and naive recursion stack-overflows on cycles. This snippet builds up the comparator step by step: a baseline that handles primitives and plain objects, a typed-aware version that respects Date / RegExp / Map / Set, and a cycle-safe production-grade implementation. Use the version that matches your data shape.