JavaScript · Junior · Question 74 of 75

What is a callback?

button.addEventListener("click", () => save());

✓Correct answer: A function passed as an argument to be called later by other code
2A function that calls itself
3A function that runs on page load only

Explanation

Event handlers, setTimeout and array methods all take callbacks. Deeply nested async callbacks ("callback hell") led to promises and async/await.

Further reading

javascript.info: Introduction: callbacks ↗

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