Find key present in HashMap

import java.util.HashMap;

import java.util.HashSet;

import java.util.Set;

public class HashMapKey {

     

public static void main(String[] args) {

HashMap  mapa =new  HashMap();

             

                 mapa.put("a", "Mukesh");

                 mapa.put("b",  "deoghar");

                 mapa.put("c",  "satsang");

                 mapa.put("d", "devsang");

                 

                   Set  se=new HashSet();

                  

       System.out.println("Keys of map" +mapa);  

   

   System.out.println("Keys of map" +mapa.keySet());

        

   System.out.print("Is c present?:" +mapa.containsKey("c"));

     

     

      }

}

 When  run  this   code  out will like this --

Keys of map{a=Mukesh, b=deoghar, c=satsang, d=devsang}

Keys of map[a, b, c, d]

Is c present?:true