Class java.util.Dictionary
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Class java.util.Dictionary
java.lang.Object
|
+----java.util.Dictionary
- public class Dictionary
- extends Object
The Dictionary class is the abstract parent of Hashtable, which maps
keys to values. Any object can be used as a key and/or value.
- See Also:
- Hashtable, hashCode, equals
-
Dictionary()
-
-
elements()
- Returns an enumeration of the elements.
-
get(Object)
- Gets the object associated with the specified key in the Dictionary.
-
isEmpty()
- Returns true if the Dictionary contains no elements.
-
keys()
- Returns an enumeration of the Dictionary's keys.
-
put(Object, Object)
- Puts the specified element into the Dictionary, using the specified
key.
-
remove(Object)
- Removes the element corresponding to the key.
-
size()
- Returns the number of elements contained within the Dictionary.
Dictionary
public Dictionary()
size
public abstract int size()
- Returns the number of elements contained within the Dictionary.
isEmpty
public abstract boolean isEmpty()
- Returns true if the Dictionary contains no elements.
keys
public abstract Enumeration keys()
- Returns an enumeration of the Dictionary's keys.
- See Also:
- elements, Enumeration
elements
public abstract Enumeration elements()
- Returns an enumeration of the elements. Use the Enumeration methods
on the returned object to fetch the elements sequentially.
- See Also:
- keys, Enumeration
get
public abstract Object get(Object key)
- Gets the object associated with the specified key in the Dictionary.
- Parameters:
- key - the key in the hash table
- Returns:
- s the element for the key or null if the key
is not defined in the hash table.
- See Also:
- put
put
public abstract Object put(Object key,
Object value)
- Puts the specified element into the Dictionary, using the specified
key. The element may be retrieved by doing a get() with the same
key. The key and the element cannot be null.
- Parameters:
- key - the specified hashtable key
- value - the specified element
- Returns:
- the old value of the key, or null if it did not have one.
- Throws: NullPointerException
- If the value of the specified
element is null.
- See Also:
- get
remove
public abstract Object remove(Object key)
- Removes the element corresponding to the key. Does nothing if the
key is not present.
- Parameters:
- key - the key that needs to be removed
- Returns:
- the value of key, or null if the key was not found.
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