@jonahsnider/util

    Class DefaultMap<K, V, D>

    A Map that has a default value for missing keys.

    const map = new DefaultMap(0);

    map.get('a'); // 0

    const map = new DefaultMap(key => key.toUpperCase());

    map.get('a'); // 'A'

    Map

    Type Parameters

    • K
    • V
    • D extends V = V

    Hierarchy (View Summary, Expand)

    Index

    Constructors

    constructor

    Methods

    [iterator] clear delete entries forEach get has keys set values

    Constructors

    • Create a new DefaultMap with a specified default value.

      Time complexity: O(n)

      Space complexity: O(n)

      Type Parameters

      • K
      • V
      • D = V

      Parameters

      • defaultValue: Exclude<D, AnyFunction>

        The default value to use for missing keys

      • Optionalentries: null | Iterable<readonly [unknown, unknown]>

      Returns DefaultMap<K, V, D>

      const map = new DefaultMap(0);

    • Create a new DefaultMap with a specified function to generate default values.

      Time complexity: O(n)

      Space complexity: O(n)

      Type Parameters

      • K
      • V
      • D = V

      Parameters

      • defaultValueFn: (key: K) => D

        The function to generate default values

      • Optionalentries: null | Iterable<readonly [unknown, unknown]>

      Returns DefaultMap<K, V, D>

      const map = new DefaultMap(key => key.toUpperCase());

    Properties

    "[toStringTag]": string
    size: number

    the number of elements in the Map.

    "[species]": MapConstructor

    Methods

    • Returns an iterable of entries in the map.

      Returns IterableIterator<[K, V]>

    • Returns void

    • Parameters

      • key: K

      Returns boolean

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

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

      Returns IterableIterator<[K, V]>

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

      Parameters

      • callbackfn: (value: V, key: K, map: Map<K, V>) => void
      • OptionalthisArg: any

      Returns void

    • Get the value for a given key, or the default value if it's missing.

      Time complexity: O(1)

      Space complexity: O(1)

      Parameters

      • key: K

        The key to get the value for

      Returns V | D

      The value for key, or the default value if it's missing

      map.get('a');

    • Parameters

      • key: K

      Returns boolean

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

    • Returns an iterable of keys in the map

      Returns IterableIterator<K>

    • 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.

      Parameters

      • key: K
      • value: V

      Returns this

    • Returns an iterable of values in the map

      Returns IterableIterator<V>

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