Question

I implemented two Hashtable as shown below.

HashMap<Integer,String> streetno=new HashMap<Integer,String>();
   streetno.put(1, "Sachin Tendulkar");
   streetno.put(2, "Dravid");
   streetno.put(3,"Sehwag");
   streetno.put(4,"Laxman");
   streetno.put(5,"Kohli");


HashMap<String,Integer> streetname=new HashMap<String,Integer>();
   streetname.put("Sachin Tendulkar",1);
   streetname.put("Dravid",2);
   streetname.put("Sehwag",3);
   streetname.put("Laxman",4);
   streetname.put("Kohli",5);
   Iterator itr=streetno.keySet().iterator();

Now I’m asking user for input. If he enters the integer I want to retrieve particular value from the 1st hash table and if user enter the string I want to read the particular integer from 2nd hashtable.

My question is “How can I read the input from the user??” Because I don’t know whether user enters the integer or string??
And I also wanted to know Can I retrieve particular value using Iterator depending on the key??

Answer 1

You can read the input as mentioned in other answers. I just tried the main logic in this way. If combining two maps can be done, you can try this way.

            String input = "Laxman";            
            HashMap<String, String> street = new HashMap<String, String>();
            street.put("1", "Sachin Tendulkar");
            street.put("2", "Dravid");
            street.put("3", "Sehwag");
            street.put("4", "Laxman");         

            for (Map.Entry<String, String> entry : street.entrySet()) { 
                System.out.println("Key = " + entry.getKey() + ", Value = " + entry.getValue());
                if (input.equals(entry.getKey())) {
                    System.out.println(entry.getValue());   
                    break;
                } else if (input.equals(entry.getValue())) {
                    System.out.println(entry.getKey());   
                    break;
                }               
            }