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Discussion on: A 12-Line JavaScript Function to Get All Combinations of an Object's Properties

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dtinth profile image
Thai Pangsakulyanont •

At first I assumed it doing this requires a recursive-like algorithm, never thought of doing it that way!

Using flatMap, we can further reduce this down to 8 lines:

function allCombinations(obj) {
  let combos = [{}]
  for (const [key, values] of Object.entries(obj)) {
    combos = combos.flatMap((combo) =>
      values.map((value) => ({ ...combo, [key]: value }))
    )
  }
  return combos
}
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nas5w profile image
Nick Scialli (he/him) •

ooo that's fancy!

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romainblatrix profile image
Romain Blatrix •

or even shorter :

type PropObject = Record<string, unknown[]>;

export const getCombinations = (obj: PropObject): PropObject[] =>
  Object.entries(obj).reduce(
    (acc, [key, values]) =>
      acc.flatMap((combo) =>
        values.map((value) => ({ ...combo, [key]: value }))
      ),
    [{}]
  );
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thanks for the inspiration :)