ConcurrentHashMap isEmpty() Method in Java

The isEmpty() method of java.util.concurrent.ConcurrentHashMap is an in-built function in Java which checks if this map contains any key-value mappings and returns a boolean value.

Syntax:

public boolean isEmpty()

Return Value: The function returns a boolean value. It returns true if the ConcurrentHashMap is empty and returns false otherwise.

Below programs illustrate the use of isEmpty() method :

Program 1: In this program the ConcurrentHashMap is non-empty.

// Java Program Demonstrate isEmpty() 
// method of ConcurrentHashMap */ 
  
import java.util.concurrent.*; 
  
class ConcurrentHashMapDemo { 
    public static void main(String[] args) 
    { 
  
        ConcurrentHashMap<Integer, String> 
            chm = new ConcurrentHashMap<Integer, String>(); 
  
        chm.put(100, "Geeks"); 
        chm.put(101, "for"); 
        chm.put(102, "Geeks"); 
  
        // Checking for the emptiness of Map 
        if (chm.isEmpty()) { 
            System.out.println("The ConcurrentHashMap"
                               + " is empty."); 
        } 
        else { 
            // Displaying the ConcurrentHashMap 
            System.out.println("The Mappings are: "
                               + chm); 
        } 
    } 
} 

Output:

The Mappings are: {100=Geeks, 101=for, 102=Geeks}

Program 2:In this program the ConcurrentHashMap is non-empty.

// Java Program Demonstrate isEmpty() 
// method of ConcurrentHashMap */ 
  
import java.util.concurrent.*; 
  
class GFG { 
    public static void main(String[] args) 
    { 
  
        ConcurrentHashMap chm = new ConcurrentHashMap(); 
  
        // Checking for the emptiness of Map 
        if (chm.isEmpty()) { 
            System.out.println("The ConcurrentHashMap"
                               + " is empty."); 
        } 
        else { 
            // Displaying the ConcurrentHashMap 
            System.out.println("The Mappings are: "
                               + chm); 
        } 
    } 
} 

Output:

The ConcurrentHashMap is empty.

Reference : https://docs.oracle.com/javase/7/docs/api/java/util/concurrent/ConcurrentHashMap.html#isEmpty()

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