i would like to display 2 or more duplicated customers using joptionpane. It is working if there is only 1 duplicate customer but unfortunately the message dialogue wasnt showing if there is 2 or more duplicated customer. Here is my code.

  public static void main(String[] args) {
    int number;

    number = Integer.parseInt(JOptionPane.showInputDialog("Enter the number of customers: "));

    int[] one = new int[number];
    int[] two = new int[number];

    for (int i = 0; i < number; i  ) {

      one[i] = Integer.parseInt(JOptionPane.showInputDialog("Customer number: "));

    }

    int y = 0;
    for (int i = 0; i < one.length - 1; i  ) {
      for (int w = i   1; w < one.length; w  ) {
        if (one[i] == one[w]) {
          two[y] = one[w];
          y = y   1;
          break;
        }

      }

      for (int p = 0; p < y - 1; p  ) {
        if (one[p] == two[p - 1]) {
          y = y - 1;
          break;
        }
      }
    }

    if (y == 0) {
      JOptionPane.showMessageDialog(null, "\nHONEST CUSTOMERS");
    } else if (y != 0) {
      JOptionPane.showMessageDialog(null, "Duplicates:");
      for (int o = 0; o < y; o  ) {
        JOptionPane.showMessageDialog(null, "Customer #"   two[o]);
        //jop.showMessageDialog(null, "Duplicates:  Customer #"   two[l]);
        //}
      }
    }
  }
}

How can i show the message dialogue if i want to show 2 or more duplicated customers? thank you for the help.

CodePudding user response：

Break down your code into the following:

1. A function that takes the two lists and return a list of pairs of duplicates.
2. A function that takes the list of duplicates and create a string stating: "Duplicates: value1, value2..."
3. Show message box.

CodePudding user response：

here is an solution for your problem using Collections:

public static Integer[] getDuplicates(Integer[] list) {

    List<Integer> duplicates = new ArrayList<>(Arrays.asList(list));
    Set<Integer> seen = new HashSet<>(Arrays.asList(list));

    for (Integer i : seen) {
        duplicates.remove(i);
    }

    Set<Integer> uniqueDuplicate = new HashSet<>(duplicates);

    return uniqueDuplicate.toArray(Integer[]::new);

}

public static void main(String[] args) {
    int number;

    number = Integer.parseInt(JOptionPane.showInputDialog("Enter the number of customers: "));

    Integer[] one = new Integer[number];

    for (int i = 0; i < number; i  ) {

        one[i] = Integer.parseInt(JOptionPane.showInputDialog("Customer number: "));

    }

    Integer[] two = getDuplicates(one);

    if (two.length == 0) {
        JOptionPane.showMessageDialog(null, "\nHONEST CUSTOMERS");
    } else {
        JOptionPane.showMessageDialog(null, "Duplicates:");
        for (int o = 0; o < two.length; o  ) {
            JOptionPane.showMessageDialog(null, "Customer #"   two[o]);
            // jop.showMessageDialog(null, "Duplicates: Customer #"   two[l]);
            // }
        }
    }
}