AbstractMap entrySet() Method in Java with Examples

Last Updated : 26 Oct, 2018

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()); 
    } 
} 
 
  

Output:

  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()); 
    } 
} 
 
  

Output:

  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.

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