A code to print the keys from two different hashMap having same values

[sinchan banerje]

HashMap<Integer, String> a = new HashMap<Integer, String>();
		HashMap<Integer, String> b = new HashMap<Integer, String>();
		HashMap<Integer, String> c = new HashMap<Integer, String>();
		a.put(2,"bc");
        a.put(3,"df");
        a.put(4,"ef");
        b.put(1,"ef");
        b.put(5,"df");

		Iterator i1 = a.entrySet().iterator();
		
		while(i1.hasNext())
		{
			Map.Entry<Integer,String> entry = (Map.Entry)i1.next();
			String value =(String)entry.getValue();
			Iterator i2 = b.entrySet().iterator();
			while(i2.hasNext())
			{
				Map.Entry<Integer,String> entry2 = (Map.Entry)i2.next();
				if(value.equalsIgnoreCase(entry2.getValue()))
                {
                    c.put(entry2.getKey(),entry2.getValue()) ;
                    if(c.get(entry.getKey())==null)
                        c.put(entry.getKey(),entry.getValue());

                }
			}
			
			
		}
		
		 System.out.println("Enter the value:");
        DataInputStream dr = new DataInputStream(System.in);
         String checkValue=null;
        try {
            checkValue = dr.readLine();
        } catch (IOException e) {
            e.printStackTrace();  
        }

       Iterator i3 = c.entrySet().iterator();
        System.out.println("The keys are: ");
       while(i3.hasNext())
       {
         Map.Entry<Integer,String> entryc= (Map.Entry<Integer,String>)i3.next();

           if(entryc.getValue().equalsIgnoreCase(checkValue))
               System.out.print(entryc.getKey()+", ");
       }

Here a is HashMap1 and b is HashMap2 , the elements displaced are keys of common values depending upon the input given...

[Nitin Surana]

I guess you are trying to put the common values from 2 maps into another map. Is that what you are trying to do?

[Campbell Ritchie]

Welcome to the Ranch
As you have already been told you can use a second map. You can use the values in the first map as keys in the second map, and lists of the keys in the first map as values in the second map.