Lesson overview · Free interview practice

Generators

Explore iterators and generators for flow control.

Topics in the full lesson
  • Introduction to Iterables and Iterators
  • Creating Custom Iterators
  • Generator Functions
  • Advanced Generator Techniques
  • Using Generators for Asynchronous Control Flow
  • Best Practices
  • Exercises

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TheoryEasy

The Iterator Protocol

Question

What is the JavaScript iterator protocol, and how do you make an object iterable without using a generator?

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TheoryEasy

Infinite Sequences with Generators

Question

How do generators make infinite sequences practical? Implement an infinite Fibonacci generator and show how to take only the first N values.

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TheoryEasy

Generator Functions vs Regular Functions

Question

How does a generator function differ from a regular function? Show the canonical "pause-and-resume" mechanic.

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TheoryEasy

Generators for Async Flow: The Bridge to `async`/`await`

Question

How were generators used for async control flow before async/await shipped? Why does understanding this history help you debug async/await today?

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Explain your reasoning or try an implementation before comparing answers.

TheoryEasy

`yield*` Delegation

Question

What does yield* do, and when is it more than just a shortcut?

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