类 CountMap<T>

只读[toStringTag]

只读size

静态 只读[species]

[iterator]

• "[iterator]"(): MapIterator<[string, { count: number; object?: T }]>

  Returns an iterable of entries in the map.

  返回 MapIterator<[string, { count: number; object?: T }]>

clear

• clear(): void

  Removes all elements from the Map.

  返回 void

delete

• delete(key: string): boolean

  参数

  • key: string

  返回 boolean

  true if an element in the Map existed and has been removed, or false if the element does not exist.

entries

• entries(): MapIterator<[string, { count: number; object?: T }]>

  Returns an iterable of key, value pairs for every entry in the map.

  返回 MapIterator<[string, { count: number; object?: T }]>

forEach

• forEach(
      callbackfn: (
          value: { count: number; object?: T },
          key: string,
          map: Map<string, { count: number; object?: T }>,
      ) => void,
      thisArg?: any,
  ): void

  Executes a provided function once per each key/value pair in the Map, in insertion order.

  参数

  • callbackfn: (
        value: { count: number; object?: T },
        key: string,
        map: Map<string, { count: number; object?: T }>,
    ) => void
  • 可选thisArg: any

  返回 void

get

• get(key: string): { count: number; object?: T } | undefined

  Returns a specified element from the Map object. If the value that is associated to the provided key is an object, then you will get a reference to that object and any change made to that object will effectively modify it inside the Map.

  参数

  • key: string

  返回 { count: number; object?: T } | undefined

  Returns the element associated with the specified key. If no element is associated with the specified key, undefined is returned.

has

• has(key: string): boolean

  参数

  • key: string

  返回 boolean

  boolean indicating whether an element with the specified key exists or not.

keys

• keys(): MapIterator<string>

  Returns an iterable of keys in the map

  返回 MapIterator<string>

set

• set(key: string, value: { count: number; object?: T }): this

  Adds a new element with a specified key and value to the Map. If an element with the same key already exists, the element will be updated.

  参数

  • key: string
  • value: { count: number; object?: T }

  返回 this

values

• values(): MapIterator<{ count: number; object?: T }>

  Returns an iterable of values in the map

  返回 MapIterator<{ count: number; object?: T }>

静态groupBy

• groupBy<K, T>(
      items: Iterable<T>,
      keySelector: (item: T, index: number) => K,
  ): Map<K, T[]>

  Groups members of an iterable according to the return value of the passed callback.

  类型参数

  • K
  • T

  参数

  • items: Iterable<T>

    An iterable.

  • keySelector: (item: T, index: number) => K

    A callback which will be invoked for each item in items.

  返回 Map<K, T[]>