Function filter

Filters an array based on a predicate function.

Example

const takePositives = filter((x: number) => x > 0);
const a = takePositives([1, 2, 3]); // [1, 2, 3]
const b = takePositives([-1, 0, 1]); // [1]
  • filter<T>(
        fn: (x: unknown) => x is T,
    ): <U>(source: readonly U[]) => Extract<U, T>[]

    Type Parameters

    • T

    Parameters

    • fn: (x: unknown) => x is T

    Returns <U>(source: readonly U[]) => Extract<U, T>[]

  • filter<V>(fn: (x: V) => boolean): <T>(source: readonly V[]) => T[]

    Type Parameters

    • V

    Parameters

    • fn: (x: V) => boolean

    Returns <T>(source: readonly V[]) => T[]