How to get value of key in HashMap

import java.util.HashMap;
import java.util.Map;

public class HashMapGetValueOfkey {
    public static void main(String[] args) {
       
    Map<Integer,String> hm = new HashMap<Integer,String>();
       
    /*
     * Associates the specified value with the specified key in
       this map (optional operation). If the map previously
       contained a mapping for the key, the old value is
       replaced by the specified value
     */
        hm.put(1,"ankush");
        hm.put(2, "amit");
        hm.put(3,"shivam");
        hm.put(4,"ankit");
        hm.put(5, "yogesh");
       
        /*
         * Returns the value to which the specified
         * key is mapped, or null if this map contains
         *  no mapping for the key.
         */
       
        System.out.println(" key = 1 and value = "+hm.get(1));
        System.out.println(" key = 1 and value = "+hm.get(10));
       
        System.out.println(" key = 1 and value = "+hm.get(5));
        System.out.println(" key = 1 and value = "+hm.get(4));
       
    }

}

Output:

 key = 1 and value = ankush

 key = 1 and value = null

 key = 1 and value = yogesh

 key = 1 and value = ankit

How to iterate through HashMap

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class HashMapIterate {
   
    public static void main(String[] args) {
       
    Map<Integer,String> hm = new HashMap<Integer,String>();
       
    /*
     * Associates the specified value with the specified key in
       this map (optional operation). If the map previously
       contained a mapping for the key, the old value is
       replaced by the specified value
     */
        hm.put(1,"ankush");
        hm.put(2, "amit");
        hm.put(3,"shivam");
        hm.put(4,"ankit");
        hm.put(5, "yogesh");
       
       Set<Integer> keys = hm.keySet();
      
       for (Integer key : keys) {
        System.out.println("key ="+key+" value = "+hm.get(key));
    }
       
       
    }
   

}


Output:

key =1 value = ankush

key =2 value = amit

key =3 value = shivam

key =4 value = ankit

key =5 value = yogesh