The AbstractMap.entrySet() method in Java is used to create a set out of the same elements contained in the map. It basically returns a set view of the abstract map or we can create a new set and store the map elements into them.
Syntax:
AbstractMap.entrySet()
Parameters: The method does not take any parameter.
Return Value: The method returns a set having same elements as the abstract map.
Below programs are used to illustrate the working of java.util.AbstractMap.entrySet() Method:
Program 1: Mapping String Values to Integer Keys.
// Java code to illustrate the entrySet() method   import java.util.*;   public class Abstract_Map_Demo {     public static void main(String[] args)     {           // Creating an empty AbstractMap         AbstractMap<Integer, String>             abs_map = new HashMap<Integer, String>();           // Mapping string values to int keys         abs_map.put( 10 , "Geeks" );         abs_map.put( 15 , "4" );         abs_map.put( 20 , "Geeks" );         abs_map.put( 25 , "Welcomes" );         abs_map.put( 30 , "You" );           // Displaying the AbstractMap         System.out.println( "Initial Mappings are: "                            + abs_map);           // Using entrySet() to get the set view         System.out.println( "The set is: "                            + abs_map.entrySet());     } } |
Initial Mappings are: {20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4} The set is: [20=Geeks, 25=Welcomes, 10=Geeks, 30=You, 15=4]
Program 2: Mapping Integer Values to String Keys.
// Java code to illustrate the entrySet() method   import java.util.*;   public class Abstract_Map_Demo {     public static void main(String[] args)     {           // Creating an empty AbstractMap         AbstractMap<String, Integer>             abs_map = new HashMap<String, Integer>();           // Mapping int values to string keys         abs_map.put( "Geeks" , 10 );         abs_map.put( "4" , 15 );         abs_map.put( "Geeks" , 20 );         abs_map.put( "Welcomes" , 25 );         abs_map.put( "You" , 30 );           // Displaying the AbstractMap         System.out.println( "Initial Mappings are: "                            + abs_map);           // Using entrySet() to get the set view         System.out.println( "The set is: "                            + abs_map.entrySet());     } } |
Initial Mappings are: {4=15, Geeks=20, You=30, Welcomes=25} The set is: [4=15, Geeks=20, You=30, Welcomes=25]
Note: The same operation can be performed with any type of Mappings with variation and combination of different data types.