C:\JDK\jdk\build\windows-x64\images\docs\api\java.base\java\util\HashMap.html

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            Java SE 13 & JDK 13DRAFT 13-internal+0-2019-04-09-0725291.pri ...
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      Module java.base
    • div[subTitle]

      Package java.util
    • h1[title]

      Class HashMap<K,​V>
  • div[contentContainer]

    • div[inheritance]

      java.lang.Object

      • div[inheritance]

        java.util.AbstractMap<K,​V>

        • div[inheritance]

          java.util.HashMap<K,​V>
    • section[description]

      • dl

        • dt

          Type Parameters:
        • dd

          K- the type of keys maintained by this map
        • dd

          V- the type of mapped values
      • dl

        • dt

          All Implemented Interfaces:
        • dd

          Serializable,Cloneable,Map<K,​V>
      • dl

        • dt

          Direct Known Subclasses:
        • dd

          LinkedHashMap,PrinterStateReasons
        public classHashMap<K,​V>extendsAbstractMap<K,&#82 ...
      • div[block]

        Hash table based implementation of theMapinterface. Thisimplement ...
      • dl

        • dt

          Since:
        • dd

          1.2
        • dt

          See Also:
        • dd

          Object.hashCode(),Collection,Map,TreeMap,Hashtable,Serialized For ...
    • section[summary]

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          • section[nestedClassSummary]

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            • h2

              Nested Class Summary
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              • h2

                Nested classes/interfaces declared in class java.util.Abstra ...
              • a[#nested.classes.inherited.from.class.java.util.AbstractMap] AbstractMap.SimpleEntry<K,​V>,AbstractMap.SimpleImmut ...
            • div[inheritedList]

              • h2

                Nested classes/interfaces declared in interface java.util.Ma ...
              • a[#nested.classes.inherited.from.class.java.util.Map] Map.Entry<K,​V>
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              Constructor Summary
            • div[memberSummary]

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                  Constructors 
                • thead

                  • tr

                    • th[colFirst]

                      Constructor
                    • th[colLast]

                      Description
                • tbody

                  • tr[altColor]

                    • th[colConstructorName]

                      HashMap()
                    • td[colLast]

                      • div[block]

                        Constructs an emptyHashMapwith the default initial capacity(16) a ...
                  • tr[rowColor]

                    • th[colConstructorName]

                      HashMap​(int initialCapacity)
                    • td[colLast]

                      • div[block]

                        Constructs an emptyHashMapwith the specified initialcapacity and ...
                  • tr[altColor]

                    • th[colConstructorName]

                      HashMap​(int initialCapacity,float loadFactor)
                    • td[colLast]

                      • div[block]

                        Constructs an emptyHashMapwith the specified initialcapacity and ...
                  • tr[rowColor]

                    • th[colConstructorName]

                      HashMap​(Map<? extendsK,​? extendsV> m)
                    • td[colLast]

                      • div[block]

                        Constructs a newHashMapwith the same mappings as thespecifiedMap
        • li[blockList]

          • section[methodSummary]

            • a[#method.summary]
            • h2

              Method Summary
            • div[memberSummary]

              • div

                • button[activeTableTab#t0] All Methods
                • button[tableTab#t2]
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                • table

                  • thead

                    • tr

                      • th[colFirst]

                        Modifier and Type
                      • th[colSecond]

                        Method
                      • th[colLast]

                        Description
                  • tbody

                    • tr[altColor#i0]

                      • td[colFirst]

                        void
                      • th[colSecond]

                        clear()
                      • td[colLast]

                        • div[block]

                          Removes all of the mappings from this map.
                    • tr[rowColor#i1]

                      • td[colFirst]

                        Object
                      • th[colSecond]

                        clone()
                      • td[colLast]

                        • div[block]

                          Returns a shallow copy of thisHashMapinstance: the keys andvalues ...
                    • tr[altColor#i2]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        compute​(K key,BiFunction<? superK,​? superV
                      • td[colLast]

                        • div[block]

                          Attempts to compute a mapping for the specified key and its curre ...
                    • tr[rowColor#i3]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        computeIfAbsent​(K key,Function<? superK,​? e ...
                      • td[colLast]

                        • div[block]

                          If the specified key is not already associated with a value (or i ...
                    • tr[altColor#i4]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        computeIfPresent​(K key,BiFunction<? superK,​ ...
                      • td[colLast]

                        • div[block]

                          If the value for the specified key is present and non-null, attem ...
                    • tr[rowColor#i5]

                      • td[colFirst]

                        boolean
                      • th[colSecond]

                        containsKey​(Object key)
                      • td[colLast]

                        • div[block]

                          Returnstrueif this map contains a mapping for thespecified key.
                    • tr[altColor#i6]

                      • td[colFirst]

                        boolean
                      • th[colSecond]

                        containsValue​(Object value)
                      • td[colLast]

                        • div[block]

                          Returnstrueif this map maps one or more keys to thespecified valu ...
                    • tr[rowColor#i7]

                      • td[colFirst]

                        Set<Map.Entry<K,​V>>
                      • th[colSecond]

                        entrySet()
                      • td[colLast]

                        • div[block]

                          Returns aSetview of the mappings contained in this map.
                    • tr[altColor#i8]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        get​(Object key)
                      • td[colLast]

                        • div[block]

                          Returns the value to which the specified key is mapped,ornullif t ...
                    • tr[rowColor#i9]

                      • td[colFirst]

                        boolean
                      • th[colSecond]

                        isEmpty()
                      • td[colLast]

                        • div[block]

                          Returnstrueif this map contains no key-value mappings.
                    • tr[altColor#i10]

                      • td[colFirst]

                        Set<K>
                      • th[colSecond]

                        keySet()
                      • td[colLast]

                        • div[block]

                          Returns aSetview of the keys contained in this map.
                    • tr[rowColor#i11]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        merge​(K key,V value,BiFunction<? superV,&#820 ...
                      • td[colLast]

                        • div[block]

                          If the specified key is not already associated with a value or is ...
                    • tr[altColor#i12]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        put​(K key,V value)
                      • td[colLast]

                        • div[block]

                          Associates the specified value with the specified key in this map ...
                    • tr[rowColor#i13]

                      • td[colFirst]

                        void
                      • th[colSecond]

                        putAll​(Map<? extendsK,​? extendsV> m)
                      • td[colLast]

                        • div[block]

                          Copies all of the mappings from the specified map to this map.
                    • tr[altColor#i14]

                      • td[colFirst]

                        V
                      • th[colSecond]

                        remove​(Object key)
                      • td[colLast]

                        • div[block]

                          Removes the mapping for the specified key from this map if presen ...
                    • tr[rowColor#i15]

                      • td[colFirst]

                        int
                      • th[colSecond]

                        size()
                      • td[colLast]

                        • div[block]

                          Returns the number of key-value mappings in this map.
                    • tr[altColor#i16]

                      • td[colFirst]

                        Collection<V>
                      • th[colSecond]

                        values()
                      • td[colLast]

                        • div[block]

                          Returns aCollectionview of the values contained in this map.
            • div[inheritedList]

              • h3

                Methods declared in class java.util.AbstractMap
              • a[#methods.inherited.from.class.java.util.AbstractMap] equals,hashCode,toString
            • div[inheritedList]

              • h3

                Methods declared in class java.lang.Object
              • a[#methods.inherited.from.class.java.lang.Object] finalize,getClass,notify,notifyAll,wait,wait,wait
            • div[inheritedList]

              • h3

                Methods declared in interface java.util.Map
              • a[#methods.inherited.from.class.java.util.Map] equals,forEach,getOrDefault,hashCode,putIfAbsent,remove,replace,
    • section[details]

      • ul[blockList]

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          • section[constructorDetails]

            • h2

              Constructor Detail
            • a[#constructor.detail]
            • ul[blockList]

              • li[blockList]

                • section[detail]

                  • h3

                    HashMap
                  • a[#(int,float)] public HashMap​(int initialCapacity,float lo ...
                  • div[block]

                    Constructs an emptyHashMapwith the specified initialcapacity and ...
                  • dl

                    • dt

                      Parameters:
                    • dd

                      initialCapacity- the initial capacity
                    • dd

                      loadFactor- the load factor
                    • dt

                      Throws:
                    • dd

                      IllegalArgumentException- if the initial capacity is negativeor t ...
              • li[blockList]

                • section[detail]

                  • h3

                    HashMap
                  • a[#(int)] public HashMap​(int initialCapacity)
                  • div[block]

                    Constructs an emptyHashMapwith the specified initialcapacity and ...
                  • dl

                    • dt

                      Parameters:
                    • dd

                      initialCapacity- the initial capacity.
                    • dt

                      Throws:
                    • dd

                      IllegalArgumentException- if the initial capacity is negative.
              • li[blockList]

                • section[detail]

                  • h3

                    HashMap
                  • a[#()] public HashMap()
                  • div[block]

                    Constructs an emptyHashMapwith the default initial capacity(16) a ...
              • li[blockListLast]

                • section[detail]

                  • h3

                    HashMap
                  • a[#(java.util.Map)] public HashMap​(Map<? extendsK,​? extendsV&gt ...
                  • div[block]

                    Constructs a newHashMapwith the same mappings as thespecifiedMap
                  • dl

                    • dt

                      Parameters:
                    • dd

                      m- the map whose mappings are to be placed in this map
                    • dt

                      Throws:
                    • dd

                      NullPointerException- if the specified map is null
        • li[blockList]

          • section[methodDetails]

            • h2

              Method Detail
            • a[#method.detail]
            • ul[blockList]

              • li[blockList]

                • section[detail]

                  • h3

                    size
                  • a[#size()] public int size()
                  • div[block]

                    Returns the number of key-value mappings in this map.
                  • dl

                    • dt

                      Specified by:
                    • dd

                      size in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      size in class AbstractMap<K,​V>
                    • dt

                      Returns:
                    • dd

                      the number of key-value mappings in this map
              • li[blockList]

                • section[detail]

                  • h3

                    isEmpty
                  • a[#isEmpty()] public boolean isEmpty()
                  • div[block]

                    Returnstrueif this map contains no key-value mappings.
                  • dl

                    • dt

                      Specified by:
                    • dd

                      isEmpty in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      isEmpty in class AbstractMap<K,​V>
                    • dt

                      Returns:
                    • dd

                      trueif this map contains no key-value mappings
              • li[blockList]

                • section[detail]

                  • h3

                    get
                  • a[#get(java.lang.Object)] public V get​(Object key)
                  • div[block]

                    Returns the value to which the specified key is mapped,ornullif t ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      get in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      get in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- the key whose associated value is to be returned
                    • dt

                      Returns:
                    • dd

                      the value to which the specified key is mapped, ornullif this map ...
                    • dt

                      See Also:
                    • dd

                      put(Object, Object)
              • li[blockList]

                • section[detail]

                  • h3

                    containsKey
                  • a[#containsKey(java.lang.Object)] public boolean containsKey​(Object key)
                  • div[block]

                    Returnstrueif this map contains a mapping for thespecified key.
                  • dl

                    • dt

                      Specified by:
                    • dd

                      containsKey in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      containsKey in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- The key whose presence in this map is to be tested
                    • dt

                      Returns:
                    • dd

                      trueif this map contains a mapping for the specifiedkey.
              • li[blockList]

                • section[detail]

                  • h3

                    put
                  • a[#put(java.lang.Object,java.lang.Object)]
                  • a[#put(K,V)] public V put​(K key,V value)
                  • div[block]

                    Associates the specified value with the specified key in this map ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      put in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      put in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key with which the specified value is to be associated
                    • dd

                      value- value to be associated with the specified key
                    • dt

                      Returns:
                    • dd

                      the previous value associated withkey, ornullif there was no mapp ...
              • li[blockList]

                • section[detail]

                  • h3

                    putAll
                  • a[#putAll(java.util.Map)] public void putAll​(Map<? extendsK,​? ex ...
                  • div[block]

                    Copies all of the mappings from the specified map to this map.The ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      putAll in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      putAll in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      m- mappings to be stored in this map
                    • dt

                      Throws:
                    • dd

                      NullPointerException- if the specified map is null
              • li[blockList]

                • section[detail]

                  • h3

                    remove
                  • a[#remove(java.lang.Object)] public V remove​(Object key)
                  • div[block]

                    Removes the mapping for the specified key from this map if presen ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      remove in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      remove in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key whose mapping is to be removed from the map
                    • dt

                      Returns:
                    • dd

                      the previous value associated withkey, ornullif there was no mapp ...
              • li[blockList]

                • section[detail]

                  • h3

                    clear
                  • a[#clear()] public void clear()
                  • div[block]

                    Removes all of the mappings from this map.The map will be empty a ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      clear in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      clear in class AbstractMap<K,​V>
              • li[blockList]

                • section[detail]

                  • h3

                    containsValue
                  • a[#containsValue(java.lang.Object)] public boolean containsValue​(Object value)
                  • div[block]

                    Returnstrueif this map maps one or more keys to thespecified valu ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      containsValue in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      containsValue in class AbstractMap<K,​V>
                    • dt

                      Parameters:
                    • dd

                      value- value whose presence in this map is to be tested
                    • dt

                      Returns:
                    • dd

                      trueif this map maps one or more keys to thespecified value
              • li[blockList]

                • section[detail]

                  • h3

                    keySet
                  • a[#keySet()] public Set<K> keySet()
                  • div[block]

                    Returns aSetview of the keys contained in this map.The set is bac ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      keySet in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      keySet in class AbstractMap<K,​V>
                    • dt

                      Returns:
                    • dd

                      a set view of the keys contained in this map
              • li[blockList]

                • section[detail]

                  • h3

                    values
                  • a[#values()] public Collection<V> values()
                  • div[block]

                    Returns aCollectionview of the values contained in this map.The c ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      values in interface Map<K,​V>
                    • dt

                      Overrides:
                    • dd

                      values in class AbstractMap<K,​V>
                    • dt

                      Returns:
                    • dd

                      a view of the values contained in this map
              • li[blockList]

                • section[detail]

                  • h3

                    entrySet
                  • a[#entrySet()] public Set<Map.Entry<K,​V>> entrySet( ...
                  • div[block]

                    Returns aSetview of the mappings contained in this map.The set is ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      entrySet in interface Map<K,​V>
                    • dt

                      Returns:
                    • dd

                      a set view of the mappings contained in this map
              • li[blockList]

                • section[detail]

                  • h3

                    computeIfAbsent
                  • a[#computeIfAbsent(java.lang.Object,java.util.function.Function)]
                  • a[#computeIfAbsent(K,java.util.function.Function)] public V computeIfAbsent​(K key,Function< ...
                  • div[block]

                    If the specified key is not already associated with a value (or i ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      computeIfAbsent in interface Map<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key with which the specified value is to be associated
                    • dd

                      mappingFunction- the mapping function to compute a value
                    • dt

                      Returns:
                    • dd

                      the current (existing or computed) value associated withthe speci ...
                    • dt

                      Throws:
                    • dd

                      ConcurrentModificationException- if it is detected that themappin ...
              • li[blockList]

                • section[detail]

                  • h3

                    computeIfPresent
                  • a[#computeIfPresent(java.lang.Object,java.util.function.BiFunction)]
                  • a[#computeIfPresent(K,java.util.function.BiFunction)] public V computeIfPresent​(K key,BiFunction
                  • div[block]

                    If the value for the specified key is present and non-null, attem ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      computeIfPresent in interface Map<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key with which the specified value is to be associated
                    • dd

                      remappingFunction- the remapping function to compute a value
                    • dt

                      Returns:
                    • dd

                      the new value associated with the specified key, or null if none
                    • dt

                      Throws:
                    • dd

                      ConcurrentModificationException- if it is detected that theremapp ...
              • li[blockList]

                • section[detail]

                  • h3

                    compute
                  • a[#compute(java.lang.Object,java.util.function.BiFunction)]
                  • a[#compute(K,java.util.function.BiFunction)] public V compute​(K key,BiFunction<? supe ...
                  • div[block]

                    Attempts to compute a mapping for the specified key and its curre ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      compute in interface Map<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key with which the specified value is to be associated
                    • dd

                      remappingFunction- the remapping function to compute a value
                    • dt

                      Returns:
                    • dd

                      the new value associated with the specified key, or null if none
                    • dt

                      Throws:
                    • dd

                      ConcurrentModificationException- if it is detected that theremapp ...
              • li[blockList]

                • section[detail]

                  • h3

                    merge
                  • a[#merge(java.lang.Object,java.lang.Object,java.util.function.BiFunction)]
                  • a[#merge(K,V,java.util.function.BiFunction)] public V merge​(K key,V value,BiFunctio ...
                  • div[block]

                    If the specified key is not already associated with a value or is ...
                  • dl

                    • dt

                      Specified by:
                    • dd

                      merge in interface Map<K,​V>
                    • dt

                      Parameters:
                    • dd

                      key- key with which the resulting value is to be associated
                    • dd

                      value- the non-null value to be merged with the existing valueass ...
                    • dd

                      remappingFunction- the remapping function to recompute a value if ...
                    • dt

                      Returns:
                    • dd

                      the new value associated with the specified key, or null if noval ...
                    • dt

                      Throws:
                    • dd

                      ConcurrentModificationException- if it is detected that theremapp ...
              • li[blockListLast]

                • section[detail]

                  • h3

                    clone
                  • a[#clone()] public Object clone()
                  • div[block]

                    Returns a shallow copy of thisHashMapinstance: the keys andvalues ...
                  • dl

                    • dt

                      Overrides:
                    • dd

                      clone in class AbstractMap<K,​V>
                    • dt

                      Returns:
                    • dd

                      a shallow copy of this map
                    • dt

                      See Also:
                    • dd

                      Cloneable
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          Java SE 13 & JDK 13DRAFT 13-internal+0-2019-04-09-0725291.pri ...
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