CODEWITHSUNDEEP
javastringif-statementintegerint
Shwheelz
Shwheelz

Reputation: 1

Convert String to int inside "if" statement

I'm working ahead in my Intro Java programming course and was wondering if there is a shortcut to what I am trying to do in an if statement.

Basically, my program receives a two-character abbreviation for a playing card and returns the full card name (i.e. "QS" returns "Queen of Spades.")

Now my question is: When I write the if statements for the numbered cards 2-10, do I need a separate statement for each number or can I combine them in one if statement?

Check where my code says IS AN INTEGER (obviously not Java notation.) Here is a fragment of my code to clarify:

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        System.out.print("Enter the card notation: ");
        String x = in.nextLine();
        if (x.substring(0,1).equals("A")){
            System.out.print("Ace");
        }
        else if(x.substring(0,1) IS AN INTEGER) <= 10)){   // question is about this line
            System.out.print(x);
        }
        else{
            System.out.println("Error.");
        }
    }
}

Upvotes: 0

Views: 6102

Answers (3)

Daniel Kaplan
Daniel Kaplan

Reputation: 67360

You can do this instead: 

    char c = string.charAt(0);
    if (Character.isDigit(c)) {
        // do something
    }

x.substring(0,1) is pretty much the same as string.charAt(0). The difference is charAt returns a char and substring returns a String.

If this weren't homework, I'd recommend you use StringUtils.isNumeric instead. You'd be able to say:

    if (StringUtils.isNumeric(x.substring(0, 1))) {
        System.out.println("is numeric");
    }

Upvotes: 5

Bohemian
Bohemian

Reputation: 425033

This is the briefest solution I can think of:

private static Map<String, String> names = new HashMap<String, String>() {{
    put("A", "Ace"); 
    put("K", "King"); 
    put("Q", "Queen"); 
    put("J", "Jack"); 
}};

then in your main:

String x = in.nextLine();
if (x.startsWith("10")) { // special case of two-character rank
    System.out.print("Rank is 10");
} else if (Character.isDigit(x.charAt(0)){
    System.out.print("Rank is " + x.charAt(0));
} else
    System.out.print("Rank is: " + names.get(x.substring(0,1));
}

Upvotes: 0

Dan
Dan

Reputation: 1179

Another way to convert a string to an int is:

Integer number = Integer.valueOf("10");

Also another approach you might consider is using a class or enum.

public class Card {
    // Feel free to change this
    public char type; // 1 - 10, J, Q, K, A
    public char kind; // Spades, Hearts, Clubs, Diamonds

    public Card(String code) {
        type = code.charAt(0);
        kind = code.charAt(1);
    }

   public boolean isGreaterThan(Card otherCard) {
       // You might want to add a few helper functions
   }
}

Upvotes: 1

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