lasan

🧩 Syntax:
import java.util.Collection;
import java.util.HashMap;
import java.util.Set;
import java.util.Iterator;
import java.util.Map;



// import javax.swing.text.html.HTMLDocument.Iterator;
class Test
{
    public static void main(String[] args) {
        HashMap<Integer,String> hm1=new HashMap<>();
        System.out.println("Size:"+hm1.size());
        System.out.println("---End of Size Method---");
        System.out.println("Is Empty:"+hm1.isEmpty());
        System.out.println("---End of IsEmpty Method---");
        hm1.put(1, "Arman");
        hm1.put(2, "Lucky");
        hm1.put(3, "Dhairya");
        System.out.println("Hm1->"+hm1);
        System.out.println(hm1.put(3, "Sumit"));
        System.out.println("Hm1->"+hm1);
        System.out.println(hm1.put(4, "Arman"));
        System.out.println("Hm1->"+hm1);
        hm1.put(null, "viren");
        System.out.println("Hm1->"+hm1);
        System.out.println(hm1.put(null, "Siya"));
        System.out.println("Hm1->"+hm1);
        System.out.println("---End of Put Method---");
        System.out.println(hm1.remove(null));
        System.out.println("Hm1->"+hm1);
        System.out.println(hm1.remove(5));
        System.out.println(hm1.remove(3,"SUM"));
        System.out.println("Hm1->"+hm1);
        System.out.println("---End of Remove Method---");
        HashMap<Integer,String> hm2=new HashMap<>();
        System.out.println(hm2.put(3,"dju"));
        System.out.println("Hm2->"+hm2);
        hm1.putAll(hm2);
        System.out.println("Hm1->"+hm1);
        System.out.println(hm1.get(1));
        System.out.println(hm1.get(2));
        System.out.println(hm1.get(3));
        System.out.println(hm1.get(4));
        System.out.println(hm1.get(5));
        System.out.println("---End of Put & PutAll Method---");
        System.out.println(hm1.containsKey(1));
        System.out.println(hm1.containsKey(2));
        System.out.println(hm1.containsKey(3));
        System.out.println(hm1.containsKey(4));
        System.out.println(hm1.containsKey(5));
        System.out.println("---End of ContainsKey Method---");
        System.out.println(hm1.containsValue("Arman"));
        System.out.println(hm1.containsValue("dju"));
        System.out.println("---End of ContainsValue Method---");
        hm1.clear();
        System.out.println("Hm1->"+hm1);
        System.out.println("---End of Clear Method---");
        HashMap<Integer,String> hm3=new HashMap<>();
        hm3.put(1,"A");
        hm3.put(2,"B");
        hm3.put(3,"C");
        System.out.println("Hm3->"+hm3);
        System.out.println(hm3.keySet());
        Set keyHm3=hm3.keySet();
        System.out.println(keyHm3);
        Iterator itr2=hm3.keySet().iterator();
        while (itr2.hasNext()) {
            System.out.println(itr2.next());
        }
        System.out.println("---End of SetKey Method---");
        System.out.println(hm3.values());
        Collection valuehm3=hm3.values();
        System.out.println(valuehm3);
        Iterator itr3=hm3.values().iterator();
        while (itr3.hasNext()) {
            System.out.println(itr3.next());
        }
        System.out.println("---End of Values Method---");
        System.out.println(hm3.entrySet());
        Set entryhm3=hm3.entrySet();
        System.out.println(entryhm3);
        Iterator itr1=hm3.entrySet().iterator();
        while (itr1.hasNext()) {
            System.out.println(itr1.next());
        }
        System.out.println("---End of EntrySet Method---");
        Iterator itr4=hm3.entrySet().iterator();
        while (itr4.hasNext()) {
            Map.Entry entry=(Map.Entry)itr4.next();
            System.out.println(entry.getKey()+"-->"+entry.getValue());
        }
        for(Map.Entry m:hm3.entrySet())
        {
            System.out.println(m.getKey()+"-->"+m.getValue());
        }
        
    }
}