Function firstItem

Returns the first item of an array.

See

at

Example

firstItem([1, 2, 3]); // => 1
firstItem([]); // => undefined
  • firstItem<S>(source): IfExtends<IsNonEmptyArray<S> extends true
        ? S[0]
        : undefined | S[number], undefined | S[number], IsNonEmptyArray<S> extends true
        ? S[0]
        : undefined | S[number], undefined | S[number]>

  • Type Parameters

    • S extends readonly unknown[]

    Parameters

    • source: S

    Returns IfExtends<IsNonEmptyArray<S> extends true
        ? S[0]
        : undefined | S[number], undefined | S[number], IsNonEmptyArray<S> extends true
        ? S[0]
        : undefined | S[number], undefined | S[number]>

    The first item of the array, or undefined if the array is empty.