Array Methods: map, filter, reduce — Free JavaScript Tutorial
Learn Array Methods: map, filter, reduce in JavaScript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.
TL;DR: Learn Array Methods: map, filter, reduce in JavaScript with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in…
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Array Methods: map, filter, reduce in JavaScript
`.map(fn)` — creates a NEW array by applying fn to each element. Does not modify original.
`.filter(fn)` — creates a NEW array with only elements where fn returns true.
`.reduce(fn, initial)` — reduces array to a single value. fn receives (accumulator, currentValue).
`.forEach(fn)` — like map but returns undefined (just runs side effects). `.find(fn)` — returns first matching element. `.every(fn)` / `.some(fn)` — all/any match.
`.sort()` — sorts in-place. For numbers: `.sort((a,b) => a-b)` ascending.
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