Arrays & Array Methods (map, filter, reduce)

const items = ['a', 'b', 'c'];
const copies = Array.from(
  { length: 3 }, 
  (_, i) => items.slice()
);

Creating array references
Creating deep copies
Creating shallow copies
Array.from creates array of shallow copies: 1) Creates new array with specified length, 2) Mapping function creates copy of items for each element, 3) slice() creates shallow copy of original array, 4) Results in array of independent arrays, 5) Each copy has same content but different reference, 6) More efficient than manual array creation, 7) Common pattern for initializing similar structures, 8) Useful for creating matrix-like structures.
Creating empty arrays