API reference › @evolu/common › Array › filterArray

Call Signature

function filterArray<T, S>(
  array: readonly T[],
  refinement: RefinementWithIndex<T, S>,
): readonly S[];

Defined in: packages/common/src/Array.ts:465

Filters an array using a predicate or refinement function, returning a new readonly array.

When used with a refinement function (with value is Type syntax), TypeScript will narrow the result type to the narrowed type, making it useful for filtering with Evolu Types like PositiveInt.is.

Example

With predicate

filterArray([1, 2, 3, 4, 5], (x) => x % 2 === 0); // [2, 4]

With refinement

const mixed: ReadonlyArray<NonEmptyString | PositiveInt> = [
  NonEmptyString.orThrow("hello"),
  PositiveInt.orThrow(42),
];
const positiveInts = filterArray(mixed, PositiveInt.is);
// positiveInts: ReadonlyArray<PositiveInt> (narrowed type)

Call Signature

function filterArray<T>(
  array: readonly T[],
  predicate: PredicateWithIndex<T>,
): readonly T[];

Defined in: packages/common/src/Array.ts:470

With predicate.

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