Cast a value as an array

Wrap a single value in an array and return arrays unchanged.

JavaScript Version 1.0.0 · MIT · .md

function castArray(value) { return Array.isArray(value) ? value : [value]; }

Input & expected output

"[email protected]"

[
  "[email protected]"
]

The edge case

[]

[]

Know the limits

• Arrays are returned as they are, not copied.
• Useful for a field that accepts one value or many, such as a list of recipients, before iterating over it.

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.