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Fundamentals · easy

11. Scope and Closures

Lexical environment and captured variables.

1 min read3 questionsup to 50 XPtopic 11/50

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A closure is the combination of a function bundled together with references to its surrounding lexical state, allowing inner functions to retain variable access.

js
function makeNonce(start = 0) {
  let n = start;
  return () => n++;
}

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Check your understanding

  1. 1. What does a closure capture?

  2. 2. Can closures cause memory leaks if retained indefinitely?

  3. 3. Why did var in for loops fail with closures?

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