Prototype Chain

Definitions

1. JavaScript's inheritance mechanism in which each object has an internal [[Prototype]] link to another object. When a property is accessed, the engine walks up this chain of linked prototypes until it finds the property or reaches null (the end of the chain, typically Object.prototype). This is how methods like toString() are available on every object.

   In plain English: A chain of linked objects in JavaScript where, if an object doesn't have a property, the language automatically checks its parent, then its grandparent, and so on.

   Example: "The method wasn't on the instance — it lives three levels up the prototype chain on the base class."

Related Terms

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• Lexical Scope
• Module Federation
• Property Descriptor
• Proxy Object
• RxJS
• Stale Closure
• Temporal Dead Zone
• Top-Level Await
• Universal Module Definition
• Zone