Get all nth items of an array

Keep every nth item, starting with the nth.

JavaScript Version 1.0.0 · MIT · .md

function getNthItems({ values, nth }) { return values.filter((_, i) => i % nth === nth - 1); }

Input & expected output

{
  "values": [
    1,
    2,
    3,
    4,
    5,
    6,
    7,
    8,
    9
  ],
  "nth": 3
}

[
  3,
  6,
  9
]

The edge case

{
  "values": [
    1,
    2
  ],
  "nth": 1
}

[
  1,
  2
]

Know the limits

• nth must be a positive integer.

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.