Ndtyjky

I have created an Array holding [24] data, and I assigned some information in each index. my problem is when I want to call the indexes using Scanner from the keyboard, let's say I called index[12] from the user, next time I call it I want it to say, u already selected that number, choose a different number so on so forth. basically, I shouldn't call the same index twice, what is the best thing to use.

your help is much needed.

Use a java.util.Set to store the selected indexed, for exmaple, java.util.HashSet.

It should look like:

Set<Integer> selected = new HashSet<>();



int userInput = ...; // get input from user



while (selected.contains(userInput)) {

    // print u already selected that number, choose a different number so on so forth

    userInput = ...; // get input from user

}





selected.add(userInput);



// do something with the index

You must save the index of selected numbers, and then you make a comparison of all new numbers with your list's elements.

Scanner s = new Scanner (System.in);

    int choice = s.nextInt();

    List<Integer> choiced = new ArrayList<Integer>();





     while (true) {//or your condition

         label:

        for (Integer i : choiced) {

            if (choice == i) {

                System.out.println("Index already selected, please select a different one");

                break label;

            }

        }

        choiced.add(choice);



        choice = s.nextInt();

    }

I tried both of your ways but still could solve it here is my code how would u have applied the codes that u guys wrote in here.

import java.util.Scanner;

public class Main {

public static void main(String args) {

    Scanner in = new Scanner(System.in);

    int number = 0;



    String  differentChocolate = new String[24];

    differentChocolate[0]  = "You receive:  A star that weighs 7 grams";

    differentChocolate[1]  = "You receive:  Praline Bag Assorted 800g";

    differentChocolate[2]  = "You receive:  Kinder Surprise Santa 75g";

    differentChocolate[3]  = "You receive:  Woolworths Christmas Chocolate Net Bag 72g";

    differentChocolate[4]  = "You receive:  Quality Street Tub 726g";

    differentChocolate[5]  = "You receive:  Cadbury Favourites Snowman Bowl 700g";

    differentChocolate[6]  = "You receive:  Lindt Santa Pouch Bag 80g";

    differentChocolate[7]  = "You receive:  Praline Bag Assorted 800g";









    while (true){

        System.out.println("Choose a chocolate (0-23): ");

                number = in.nextInt();

                System.out.println(differentChocolate[number]);

            }

        }

    }