Create cartesian product

Combine one item from each set in every possible way.

JavaScript Version 1.0.0 · MIT · .md

function cartesian(sets) { return sets.reduce((product, set) => product.flatMap(prefix => set.map(item => [...prefix, item])), [[]]); }

Input & expected output

[
  [
    "node",
    "curl"
  ],
  [
    "sandbox",
    "live"
  ]
]

[
  [
    "node",
    "sandbox"
  ],
  [
    "node",
    "live"
  ],
  [
    "curl",
    "sandbox"
  ],
  [
    "curl",
    "live"
  ]
]

The edge case

[]

[
  []
]

Know the limits

• The result size is the product of the set sizes; the lab caps it at 1,000 combinations.
• The original took sets as separate arguments.

The function above is the implementation used by the lab. The lab validates JSON types and caps size before execution; include equivalent validation when accepting untrusted input in your application.

Keep exploring

• Clone an array — Create a new array without copying the objects inside it.
• Remove duplicate values — Keep the first occurrence of each value, in its original order.
• Flatten a nested array — Turn a nested array into one sequence of values.