Cartesian product
JavaScript, Math · Dec 29, 2020

Calculates the cartesian product of two arrays.
- Use
Array.prototype.reduce()
,Array.prototype.map()
and the spread operator (...
) to generate all possible element pairs from the two arrays.
const cartesianProduct = (a, b) =>
a.reduce((p, x) => [...p, ...b.map(y => [x, y])], []);
cartesianProduct(['x', 'y'], [1, 2]);
// [['x', 1], ['x', 2], ['y', 1], ['y', 2]]