Swap two array items

Return a copy with the items at i and j exchanged.

JavaScript Version 1.0.0 · MIT · .md

function swapItems({ values, i, j }) { const copy = [...values]; [copy[i], copy[j]] = [copy[j], copy[i]]; return copy; }

Input & expected output

{
  "values": [
    "a",
    "b",
    "c",
    "d"
  ],
  "i": 0,
  "j": 3
}

[
  "d",
  "b",
  "c",
  "a"
]

The edge case

{
  "values": [
    0,
    1
  ],
  "i": 0,
  "j": 1
}

[
  1,
  0
]

Know the limits

• The original only swapped when both items were truthy, so arrays containing 0 or "" were returned unchanged. Destructuring swaps any values and works in either index order.

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.