CODEWITHSUNDEEP
javahashmaptry-catch
Mariel
Mariel

Reputation: 169

Catch with false containsValue(Hashmap)

I want my program to show an error message if I inputted wrong value in type and value.

The error message works well on type but it does not work on the value. What's wrong with it?

Map<String, String> Heart = new HashMap();

Heart.put("A", "Heart");
Heart.put("J", "Heart");
Heart.put("Q", "Heart");
Heart.put("K", "Heart");
Heart.put("2", "Heart");
Heart.put("3", "Heart");
Heart.put("4", "Heart");
Heart.put("5", "Heart");
Heart.put("6", "Heart");
Heart.put("7", "Heart");
Heart.put("8", "Heart");
Heart.put("9", "Heart");
Heart.put("10", "Heart");

System.out.print("Value: ");
val = input.next();
System.out.print("Type: ");
typ = input.next();
if(typ.equals("Heart")){
   if(Heart.containsKey(val)&&Heart.containsValue(typ)){
       System.out.println(val+" of "+typ+" is successfully added.\n");
   }
   if(Heart.containsKey(val)==false){
       try{
         throw new InvalidValueException();
       }
       catch(InvalidValueException e){
         System.out.println(e.getMessage()+" 2-10, AJQK.\n");
       }
   }
   else if(Heart.containsValue(typ)==false){
       try{
         throw new InvalidValueException();
       }
       catch(InvalidValueException e){
          System.out.println(e.getMessage()+" HDSC\n");
       }
    }
 }

Upvotes: 0

Views: 33

Answers (1)

Akash Thakare
Akash Thakare

Reputation: 22972

If you have same value for all the keys, you should create a List<String> of types instead of using Map. Then you can just allow user to input type and check whether List#contains the type or not.

If it's just an example and you will have different value for each type then,

  • You can just throw Exception with message no need to catch and print message. You can pass message in constructor.

  • If type is value and val is key, then typ.equals("Heart") check is redundant, as you are checking Heart.containsValue(typ).

  • So, if your typ is not Heart you will not able to enter the condition and if(Heart.containsKey(val)==false){ will never be true if typ is not Heart.

  • You should remove the if(typ.equals("Heart")) check.

It's better to follow naming convention start variable name with lowercase.

Upvotes: 1

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