How would you explain Prototype Chain and Inheritance to a junior engineer?

Answers use simple, clear English.

Quick interview answer

Explain Prototype Chain and Inheritance in one sentence, then a tiny example, then one “don’t do this” tip. Mitigate first, then root-cause. Check symptoms against: Confusing __proto__ with prototype property on functions; shadowing constructor incorrectly..

Detailed answer

Junior-friendly explanation of Prototype Chain and Inheritance: Plain English: Mitigate first, then root-cause. Check symptoms against: Confusing __proto__ with prototype property on functions; shadowing constructor incorrectly.. Tiny example: Array instances inherit push/pop from Array.prototype; custom types extend via Object.create or class extends. One warning: Confusing __proto__ with prototype property on functions; shadowing constructor incorrectly.

Full explanation

Keep jargon low, then layer detail. Objects delegate property lookup via [[Prototype]]. Constructor.prototype is shared by instances. class is syntactic sugar over prototypes; methods live on prototype.

Follow-up questions

Only answered follow-ups are shown — click to open with full answers

Parent context — Prototype Chain and Inheritance

Mitigate first, then root-cause. Check symptoms against: Confusing __proto__ with prototype property on functions; shadowing constructor incorrectly..

View full parent question →

#js-prototype-chain#senior