first

Callable

• first<T>(xs: T): T extends readonly [infer N0, ...unknown[]] ? N0 : Maybe<IterableElement<T>>

---

• Return the first element of a traversable, or Nothing if the traversable is empty.

  The first function is a good example of how to use the at function. It's also a good example of how to use the Maybe type.

  Example

  first([1, 2, 3])
  // => 1
  
  first([])
  // => Nothing

  @see

  at

  ---

  Type parameters

  • T: Traversable<unknown, unknown> | readonly unknown[]

    The element type.

  Parameters

  • xs: T

    The traversable to find the element in.

  Returns T extends readonly [infer N0, ...unknown[]] ? N0 : Maybe<IterableElement<T>>

  The first element of the traversable, otherwise Nothing.