Function reduce

reduce
 | AsyncIterable<unknown, any, any>,
 R,
>(
 iterable: I,
 reducer: (acc: IterableItem, value: IterableItem, index: number) => R,
): ReduceResult<I, R>
Reduces values of an iterable (Array, Set, Iterable, AsyncIterable) into a single value using the provided reducer function.

Works with:
- Synchronous iterables (Array, Set, custom Iterable)
- Asynchronous iterables (AsyncIterable / async generators)
- Synchronous or asynchronous reducer functions (if the reducer returns a promise the result becomes a promise)
If the initial value isn't provided, the first emitted value is used as the accumulator (same semantics as Array.prototype.reduce). When used with an empty iterable without an initial value an error is thrown.
Type Parameters
- I extends Iterable<unknown, any, any> | AsyncIterable<unknown, any, any>
- R
Parameters
- iterable: I
- reducer: (acc: IterableItem, value: IterableItem, index: number) => R
Returns ReduceResult<I, R>
Example
```
reduce([1,2,3], (a,b) => a + b, 0) // 6
reduce(new Set(['a','b']), (a,b) => a + b) // 'ab'
await reduce(asyncGen(), (a,b) => a + b) // 6
```
- Defined in src/iterable.ts:101
reduce
 | AsyncIterable<unknown, any, any>,
 R,
>(
 iterable: I,
 reducer: (acc: Awaited<R>, value: IterableItem, index: number) => R,
 initial: Awaited<R>,
): ReduceResult<I, R>
Reduces values of an iterable (Array, Set, Iterable, AsyncIterable) into a single value using the provided reducer function.

Works with:
- Synchronous iterables (Array, Set, custom Iterable)
- Asynchronous iterables (AsyncIterable / async generators)
- Synchronous or asynchronous reducer functions (if the reducer returns a promise the result becomes a promise)
If the initial value isn't provided, the first emitted value is used as the accumulator (same semantics as Array.prototype.reduce). When used with an empty iterable without an initial value an error is thrown.
Type Parameters
- I extends Iterable<unknown, any, any> | AsyncIterable<unknown, any, any>
- R
Parameters
- iterable: I
- reducer: (acc: Awaited<R>, value: IterableItem, index: number) => R
- initial: Awaited<R>
Returns ReduceResult<I, R>
Example
```
reduce([1,2,3], (a,b) => a + b, 0) // 6
reduce(new Set(['a','b']), (a,b) => a + b) // 'ab'
await reduce(asyncGen(), (a,b) => a + b) // 6
```
- Defined in src/iterable.ts:105

Function reduce

Type Parameters

Parameters

Returns ReduceResult<I, R>

Example

Type Parameters

Parameters

Returns ReduceResult<I, R>

Example

Settings