Frontend · Mid-level · Theory

Explain how prototypal inheritance works in JavaScript, and what actually happens when you write a class with extends.

~4 min by voice

How to approach it

They're checking whether you understand the real mechanics of objects in JS — the prototype chain — and whether you see constructor functions and linked prototypes behind the class/extends syntax, rather than "copying methods like in Java."

Have you seen this question in a real interview?

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Topics

prototypes javascript

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Answer by voice

The interviewer will ask this question and listen. Think out loud and ask for a hint if you need one. When you're done, pause or tap “That's my answer”. In about a minute, your score and the points you covered show up here.

Best with headphones · ~4 min