Function where

where<TElement, TFiltered>(
source: Iterable<TElement>,
predicate: IndexedTypePredicate<TElement, TFiltered>,
): IEnumerable<TFiltered>
Filters source using a type guard predicate and narrows the resulting element type.
Type Parameters
- TElement
  Type of elements within source.
- TFiltered
  extends TElement Narrowed element type produced by predicate.
Parameters
- source: Iterable<TElement>
  The iterable to filter.
- predicate: IndexedTypePredicate<TElement, TFiltered>
  Type guard invoked with each element and its zero-based index. Return true to keep the element in the results.
Returns IEnumerable<TFiltered>
A deferred sequence containing only elements that satisfy the type guard.
Throws
Re-throws any error thrown while iterating source or executing predicate.

Remarks
Enumeration is lazy; predicate executes on demand and may be invoked again when consumers restart iteration.
Example
```
const numbers = [1, 2, 3, 4, 5];
const evenNumbers = where(numbers, x => x % 2 === 0).toArray();
console.log(evenNumbers); // [2, 4]
```
- Defined in src/enumerator/functions/where.ts:21
where<TElement>(
source: Iterable<TElement>,
predicate: IndexedPredicate<TElement>,
): IEnumerable<TElement>
Filters source using a predicate that can inspect both the element and its position.
Type Parameters
- TElement
  Type of elements within source.
Parameters
- source: Iterable<TElement>
  The iterable to filter.
- predicate: IndexedPredicate<TElement>
  Predicate invoked with each element and its zero-based index. Return true to keep the element in the results.
Returns IEnumerable<TElement>
A deferred sequence containing only the elements that satisfy predicate.

Throws
Re-throws any error thrown while iterating source or executing predicate.

Remarks
Enumeration is lazy; predicate executes on demand and iteration stops as soon as the consumer stops reading.
- Defined in src/enumerator/functions/where.ts:35

Function where

Type Parameters

Parameters

Returns IEnumerable<TFiltered>

Throws

Remarks

Example

Type Parameters

Parameters

Returns IEnumerable<TElement>

Throws

Remarks

Settings