JavaScript · Junior · Question 69 of 75

Why does `document.querySelectorAll("li").map(...)` throw?

✓Correct answer: It returns a NodeList, not an array; use Array.from(...) or spread to get map
2querySelectorAll returns null when nothing is found
3map can't be used with DOM elements

Explanation

A NodeList has forEach and is iterable, but lacks most array methods. It is also static: it doesn't update when the DOM changes.

Further reading

javascript.info: Searching: getElement*, querySelector* ↗

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