reduceItems()function
reduceItems(items: Iterable<T>, reducer: (previous: T, item: T) => T, initial: T): T
reduceItems(items: Iterable<T>, reducer: (previous: T | undefined, item: T) => T, initial?: T): T | undefined
reduceItems(items: Iterable<I>, reducer: (previous: O, item: I) => O, initial: O): O
reduceItems(items: Iterable<I>, reducer: (previous: O | undefined, item: I) => O, initial?: O): O | undefined
| Param | Type | |
|---|---|---|
items | Iterable<T> | The iterable to reduce. required |
reducer | (previous: T, item: T) => T | Reducer called with the previous accumulated value and the current item, returning the next accumulated value. required |
initial | T | The initial accumulated value. required |
items | Iterable<T> | required |
reducer | (previous: Tundefined, item: T) => T | required |
initial | T | |
items | Iterable<I> | required |
reducer | (previous: O, item: I) => O | required |
initial | O | required |
reducer | (previous: Oundefined, item: I) => O | required |
initial | O |
| Return | |
|---|---|
T | The final accumulated value, or undefined if the iterable is empty and no initial was given. |
T | undefined | |
O | |
O | undefined |
Reduce an iterable set of items using a reducer function.
- Calls
reducerfor each item, threading the accumulated value through.
Examples
reduceItems([1, 2, 3], (a, b) => a + b, 0) // 6