Java IdentityHashMap isEmpty() method

The isEmpty() method of the Java IdentityHashMap is used to check whether the calling IdentityHashMap is empty or not.

Syntax

Return

True, if the calling IdentityHashMap is empty.

Example 1

import java.util.IdentityHashMap;

public class IdentityHashMapIsEmptyExample1 {
    public static void main(String[] args) {
   //Creating an object of IdentityHashMap class
   IdentityHashMap<String,Integer> map1 = new IdentityHashMap<String,Integer>(6);
   
   //Creating another object of IdentityHashMap
   IdentityHashMap<String,Integer> map2 = new IdentityHashMap<String,Integer>();
   
   //Putting key-value pairs inside map
   map1.put("Java", 1);
   map1.put("is", 2);
   map1.put("the", 3);
   map1.put("best", 4);
   map1.put("programming", 5);
   map1.put("language", 6);
 
   //Checking whether the map1 and map2 IdentityHashMap is empty or not
   System.out.println(map1.isEmpty());
   System.out.println(map2.isEmpty());
}
}

Output:

false
true

Example 2

import java.util.IdentityHashMap;

class Student{
    private int roll;
    private String name;
    private int standard;
    
    public Student(int roll,String name,int standard){
        this.roll = roll;
        this.name = name;
        this.standard = standard;
    }
    
    public String disp(){
        return roll+" "+name+" "+standard;
    }
}

public class IdentityHashMapIsEmptyExample2 {
    public static void main(String[] args) {
        
        //Creating Objects of Student class
        Student stud1 = new Student(1 ,"Ram ",10);
        Student stud2 = new Student(2 ,"Shyam ",10);
        Student stud3 = new Student(3 ,"Aman ",12);
        Student stud4 = new Student(4 ,"Harsh ",12);
        Student stud5 = new Student(5 ,"Shivam",11);
        
        //Creating an instance of IdentityHashMap
        IdentityHashMap<Integer,Student> map = new IdentityHashMap<Integer,Student>(5);
        IdentityHashMap<Integer,Student> map1 = new IdentityHashMap<Integer,Student>(5);
                
        //Inserting the Student class objects into IdentityHashMap
        map.put(1,stud1);
        map.put(2,stud2);
        map.put(3,stud3);
        map.put(4,stud4);        
        //Checking if this map and map1 are empty
        System.out.println(map.isEmpty());
        System.out.println(map1.isEmpty());
}
}

Output: