- reduceByKey<S, T>(subject, callbackfn, initialValue): T
Type Parameters
- S extends Record<string | number | symbol, any>
- T
Parameters
- subject: S
- callbackfn: ((previousValue: T, key: keyof S, currentIndex: number, array: string[], subject: S) => T)
- (previousValue, key, currentIndex, array, subject): T
Parameters
- previousValue: T
- key: keyof S
- currentIndex: number
- array: string[]
- subject: S
Returns T
- initialValue: T
Returns T