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Java - Dictionary Class

Quiz

Dictionary is an abstract class that represents a key/value storage repository and operates much like Map.

Given a key and value, you can store the value in a Dictionary object. Once the value is stored, you can retrieve it by using its key. Thus, like a map, a dictionary can be thought of as a list of key/value pairs.

The abstract methods defined by Dictionary are listed below −

Sr.No.	Method & Description
1	Enumeration elements( ) Returns an enumeration of the values contained in the dictionary.
2	Object get(Object key) Returns the object that contains the value associated with the key. If the key is not in the dictionary, a null object is returned.
3	boolean isEmpty( ) Returns true if the dictionary is empty, and returns false if it contains at least one key.
4	Enumeration keys( ) Returns an enumeration of the keys contained in the dictionary.
5	Object put(Object key, Object value) Inserts a key and its value into the dictionary. Returns null if the key is not already in the dictionary; returns the previous value associated with the key if the key is already in the dictionary.
6	Object remove(Object key) Removes the key and its value. Returns the value associated with the key. If the key is not in the dictionary, a null is returned.
7	int size( ) Returns the number of entries in the dictionary.

The Dictionary class is obsolete. You should implement the Map interface to obtain key/value storage functionality.

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