public class HashMap extends java.lang.Object implements Map, Serializable
HashMap
,
Serialized FormConstructor and Description |
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HashMap()
Default constructor, creates a new empty Map
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HashMap(int s)
Constructor, creates a new Map with initial size
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HashMap(int s,
float lf)
Constructor, creates a new Map with initial size and load factor
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Modifier and Type | Method and Description |
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void |
clear()
Remove all mappings from this map.
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boolean |
containsKey(java.lang.Object key)
Returns true if this map contains a mapping for the specified
key.
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java.lang.Object |
get(java.lang.Object key)
Returns the value to which this map maps the specified
key.
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boolean |
isEmpty()
Returns true if this map contains no key-value mappings.
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Set |
keySet()
Returns a set view of the keys contained in this map.
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java.lang.Object |
put(java.lang.Object key,
java.lang.Object value)
Associates the specified value with the specified key in this map
(optional operation).
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java.lang.Object |
remove(java.lang.Object o)
Removes the mapping for this key from this map if present (optional
operation).
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int |
size()
Returns the number of mappings in this map.
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java.lang.String |
toString() |
Collection |
values()
Returns a Collection view of the values contained in this map.
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public HashMap()
public HashMap(int s)
public HashMap(int s, float lf)
public boolean isEmpty()
Map
public java.lang.Object remove(java.lang.Object o)
Map
public java.lang.Object put(java.lang.Object key, java.lang.Object value)
Map
public java.lang.Object get(java.lang.Object key)
Map
public int size()
Map
public boolean containsKey(java.lang.Object key)
Map
containsKey
in interface Map
key
- key whose presence in this map is to be tested.interface
public void clear()
Map
public java.lang.String toString()
toString
in class java.lang.Object
public Set keySet()
Map
public Collection values()
Map