Java IdentityHashMap keySet() method

The keyset() method of the Java IdentityHashMap class is used to get a set view of all the keys contained in the calling IdentityHashMap.

Syntax

Return

A set containing all the keys contained in the calling IdentityHashMap

Example 1

import java.util.IdentityHashMap;

public class IdentityHashMapKeySetExample1 {
    public static void main(String[] args) {
   //Creating an object of IdentityHashMap class
   IdentityHashMap<String,Integer> map = new IdentityHashMap<String,Integer>(6);
   
   //Putting key-value pairs inside map
   map.put("Java", 1);
   map.put("is", 2);
   map.put("the", 3);
   map.put("best", 4);
   map.put("programming", 5);
   map.put("language", 6);
   
   //All the Linkages in the IdentityHashMap
   System.out.println(map);
   
   //Displaying the set view of all the keys
   System.out.println(map.keySet());
}
}

Output:

{Java=1, the=3, language=6, programming=5, best=4, is=2}
[Java, the, language, programming, best, is]

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 IdentityHashMapKeySetExample2 {
    public static void main(String[] args) {
        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);

        //Creating an instance of IdentityHashMap  
        IdentityHashMap<Integer,Student> map = 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);
        
        //Displaying the set view of all the keys
        System.out.println(map.keySet());
    }
}

Output: