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LetsGit.IT/Categories/JavaScript
JavaScriptmedium

Explain prototypal inheritance in JavaScript.

Tags
#prototypes#inheritance
Back to categoryPractice quiz

Answer

Objects inherit from other objects via the prototype chain. Property lookups walk up the chain until found or null. You can create links with Object.create or class syntax.

Advanced answer

Deep dive

Expanding on the short answer — what usually matters in practice:

  • Context (tags): prototypes, inheritance
  • Explain the "why", not just the "what" (intuition + consequences).
  • Trade-offs: what you gain/lose (time, memory, complexity, risk).
  • Edge cases: empty inputs, large inputs, invalid inputs, concurrency.

Examples

A tiny example (an explanation template):

// Example: discuss trade-offs for "explain-prototypal-inheritance-in-javascript."
function explain() {
  // Start from the core idea:
  // Objects inherit from other objects via the prototype chain. Property lookups walk up the c
}

Common pitfalls

  • Too generic: no concrete trade-offs or examples.
  • Mixing average-case and worst-case (e.g., complexity).
  • Ignoring constraints: memory, concurrency, network/disk costs.

Interview follow-ups

  • When would you choose an alternative and why?
  • What production issues show up and how do you diagnose them?
  • How would you test edge cases?

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