mergeMap() function

Merge the source map into the target map, replacing keys that already exist.

Signature:

export declare function mergeMap<TKey, TVal>(target: Map<TKey, TVal>, source: Map<TKey, TVal> | ReadonlyArray<[TKey, TVal]>): Map<TKey, TVal>;

Parameters

Parameter	Type	Description
target	Map<TKey, TVal>
source	Map<TKey, TVal> \| ReadonlyArray<[TKey, TVal]>

Returns:

Map<TKey, TVal>