Map Interface

A map contains values based on the key i.e. key and value pair.Each pair is known as an entry.Map contains only unique elements.

Commonly used methods of Map interface:

  1. public Object put(object key,Object value): is used to insert an entry in this map.
  2. public void putAll(Map map):is used to insert the specifed map in this map.
  3. public Object remove(object key):is used to delete an entry for the specified key.
  4. public Object get(Object key):is used to return the value for the specified key.
  5. public boolean containsKey(Object key):is used to search the specified key from this map.
  6. public boolean containsValue(Object value):is used to search the specified value from this map.
  7. public Set keySet():returns the Set view containing all the keys.
  8. public Set entrySet():returns the Set view containing all the keys and values.

Entry

Entry is the subinterface of Map.So we will access it by Map.Entry name.It provides methods to get key and value.

Methods of Entry interface:

  1. public Object getKey(): is used to obtain key.
  2. public Object getValue():is used to obtain value.