Package org.apache.commons.collections4

# Interface Put<K,V>

Type Parameters:
  `K` - The type of the keys in this map.
  `V` - The type of the values in this map.

All Known Subinterfaces:
  `BidiMap<K,V>`, `BoundedMap<K,V>`, `IterableMap<K,V>`, `IterableSortedMap<K,V>`, `MultiMap<K,V>`, `OrderedBidiMap<K,V>`, `OrderedMap<K,V>`, `SortedBidiMap<K,V>`, `Trie<K,V>`

All Known Implementing Classes:
  `AbstractBidiMapDecorator`, `AbstractBitwiseTrie`, `AbstractDualBidiMap`, `AbstractHashedMap`, `AbstractIterableMap`, `AbstractLinkedMap`, `AbstractMapDecorator`, `AbstractOrderedBidiMapDecorator`, `AbstractOrderedMapDecorator`, `AbstractPatriciaTrie`, `AbstractReferenceMap`, `AbstractSortedBidiMapDecorator`, `AbstractSortedMapDecorator`, `CaseInsensitiveMap`, `CompositeMap`, `DefaultedMap`, `DualHashBidiMap`, `DualLinkedHashBidiMap`, `DualTreeBidiMap`, `DualTreeBidiMap.ViewMap`, `FixedSizeMap`, `FixedSizeSortedMap`, `Flat3Map`, `HashedMap`, `LazyMap`, `LazySortedMap`, `LinkedMap`, `ListOrderedMap`, `LRUMap`, `MultiKeyMap`, `MultiValueMap`, `PassiveExpiringMap`, `PatriciaTrie`, `PredicatedMap`, `PredicatedSortedMap`, `ReferenceIdentityMap`, `ReferenceMap`, `SingletonMap`, `StaticBucketMap`, `TransformedMap`, `TransformedSortedMap`, `TransformedSplitMap`, `TreeBidiMap`, `UnmodifiableBidiMap`, `UnmodifiableMap`, `UnmodifiableOrderedBidiMap`, `UnmodifiableOrderedMap`, `UnmodifiableSortedBidiMap`, `UnmodifiableSortedMap`, `UnmodifiableTrie`

public interface Put<K,V>
The "write" subset of the `Map` interface.

NOTE: in the original `Map` interface, `Map.put(Object, Object)` is known to have the same return type as `Map.get(Object)`, namely `V`. `Put` makes no assumptions in this regard (there is no association with, nor even knowledge of, a "reading" interface) and thus defines `put(Object, Object)` as returning `Object`.

Since:
  4.0
See Also:
  - `Get`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `clear()`
  Removes all of the mappings from this map.
  `Object`
  `put(K key, V value)`
  Associates the specified value with the specified key in this map.
  `void`
  `putAll(Map<? extends K,? extends V> t)`
  Copies all of the mappings from the specified map to this map.

- ## Method Details

  - ### clear

    void clear()
    Removes all of the mappings from this map.
    See Also:
      - `Map.clear()`

  - ### put

    Object put(K key, V value)
    Associates the specified value with the specified key in this map.

    Note that the return type is Object, rather than V as in the Map interface. See the class Javadoc for further info.

    Parameters:
      `key` - key with which the specified value is to be associated.
      `value` - value to be associated with the specified key.
    Returns:
      The previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`, if the implementation supports `null` values.)
    See Also:
      - `Map.put(Object, Object)`

  - ### putAll

    void putAll(Map<? extends K,? extends V> t)
    Copies all of the mappings from the specified map to this map.
    Parameters:
      `t` - mappings to be stored in this map.
    See Also:
      - `Map.putAll(Map)`