Random element from int to String?

Question

Okay, so I'll first show my code, then I'll explain what I need help with.

  Random isServerChance = new Random();
  Random isGood = new Random();
  Random isBad = new Random();

  // Some IDs which are considered "Good"
  int isGoodTable[] =
  { 1038, 1040, 1042, 1044 };
  // Some IDs which are considered "Bad"
  int isBadTable[] =
  { 6570, 6585, 952, 969 };
  // Based on this roll, will pick which cat is used. Good, or Bad.
  int isServerRoll = isServerChance.nextInt(6);
  // If it's > 3 it's going to be a "Good" item, if it's not, it's a bad
  // item.
  if (isServerRoll > 3)
  {

     int isGoodValue = isGood.nextInt(isGoodTable.length);
     System.out.println("You've received a rare item! You got a: " + isGoodTable[isGoodValue]);

  } else
  {
     int isBadValue = isBad.nextInt(isBadTable.length);
     System.out.println("You've received a normal item. You've got a: " + isBadTable[isBadValue]);

  }

}

Okay, so this will print: You've received a normal item. You've got a: 969 || You've received a rare item! You got a: 1042.

Let's say the int value of 969 is a Spade. Is it possible for me to make 969 equal to an array of Strings from one of the int tables above?

So, if I land on 969, it'll say: "You've received a normal item. You've got a: Spade!"

I'm sort of new, so I'm not sure if this is even possible, but I don't want to make loads of if statements for each ID.

Thanks

You can use a Hash(Set, Map), but this won't work with ints, so use Integer class to wrap it. — Joqus
– Joqus, Commented Dec 22, 2013 at 22:35

JB Nizet · Accepted Answer · 2013-12-22 22:37:08Z

6

It seems that you simply want arrays of Strings rather than arrays of integers:

String[] isBadTable = { "Foo", "Bar", "Baz", "Spade" };

Read the tutorial on arrays.

answered Dec 22, 2013 at 22:37

JB Nizet

694k94 gold badges1.3k silver badges1.3k bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

user3128007 Over a year ago

I can't get a Random value from a String though. It'd have to be an int value, then it would need to parse to a String, or is there another way? The way I have it now, it needs an int to run a dice roll. Or is there another way?

Ian McLaird Over a year ago

I like this answer better than my own, but I'll leave mine as a potentially useful alternative. @user3128007, you're choosing a random index into the array, so this should still work.

JB Nizet Over a year ago

Where in the code are you "getting a random value from a string". The length of an array of Strings is still an int. So isBad.nextInt(isBadTable.length) will still work as before.

Ian McLaird · Accepted Answer · 2013-12-22 22:40:55Z

2

Yes. Use a Map<Integer, String>. You could put your items in like this

Map<Integer, String> itemMap = new HashMap<Integer, String>();
itemMap.put(969, "Spade");
// etc.

Then you can retrieve your values like this

String itemName = itemMap.get(969);  // spade

If you do this, just be careful, because a HashMap doesn't have any default value, so if the key you try to use isn't in the Map you'll get null back.

answered Dec 22, 2013 at 22:40

Ian McLaird

5,5852 gold badges25 silver badges31 bronze badges

Comments

Leo Izen · Accepted Answer · 2013-12-22 22:42:20Z

You can use enums to solve this problem. For example, you could do

public enum CardSuit {
    SPADE(969, "Spades"),
    HEART(952, "Hearts"),
    DIAMOND(6585, "Diamonds"),
    CLUB(6570, "Clubs");

    private final int value;
    private final String name;

    private CardSuit(int value, String name){
        this.value = value;
        this.name = name;
    }

    public int getValue(){
        return value;
    }

    public String toString(){
        return name;
    }

}

Now, you can make an array of CardSuit by using

CardSuit[] suits = CardSuit.class.getEnumConstants();

and you can map the spades to the 969 by calling CardSuit.SPADE.getValue(). Use a Map<Integer, CardSuit> to do a lookup in the other direction.

See The Java Tutorials on Enums for a comprehensive tutorial.

Slate · Accepted Answer · 2013-12-22 22:42:22Z

0

Assuming you need the IDs and Strings (rather than a String table and just use the index as an ID), it looks like you want some sort of HashMap.

import java.util.HashMap;


HashMap<Integer, String[]> IDs = new HashMap<>();
IDs.put(969, new String[]{"Spade", "Shovel"} ); // Setting up your HashMap

// Recalling later
int randomID = 969; 
String[] items = IDs.get(randomID); // items will be "Spade", "Shovel", will be null if the ID is not in the HashMap.

HashMap documentation: http://docs.oracle.com/javase/6/docs/api/java/util/HashMap.html

answered Dec 22, 2013 at 22:42

Slate

3,7941 gold badge34 silver badges32 bronze badges

Comments

Thorn · Accepted Answer · 2013-12-22 22:53:58Z

0

You have the basic idea down. We don't generate random Strings, only random numbrrs. There is no point in declaring more than one Random object. Use one Random generator to create all the numbers you need.

As a beginner, I would not recommend maps to then create a correspondence between the number in the array (item #). You could put the correspondence into a text file. If you will have many items, this is the way to go. Searching through a text file is a good exercise.

answered Dec 22, 2013 at 22:53

Thorn

4,0674 gold badges25 silver badges43 bronze badges

Collectives™ on Stack Overflow

Random element from int to String?

5 Answers 5

3 Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

3 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related