Java - The Dictionary Class
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The Dictionary class is obsolete.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.
