Type Alias Head<T, D>

Head: Tuple.Head<T, D>

Gets the type of the first element of a readonly array or tuple T. If the array is empty, it returns the default type D (defaults to never). Delegates to Tuple.Head.

Type Parameters

T extends readonly unknown[]
The readonly array or tuple type.
D = never
The default type to return if T is empty. Defaults to never.

Returns

The type of the first element, or D if T is empty.

Example

type H1 = List.Head<[1, 2, 3]>; // 1
type H2 = List.Head<readonly string[]>; // string
type H3 = List.Head<[]>; // never
type H4 = List.Head<[], 'default'>; // 'default'

Type Alias Head<T, D>

Type Parameters

Returns

Example

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