How do I print data stored in if statement multiple time?

Question

So how do I make the data stored in a variable to store each time before displaying it in the end.

I have a for loop statement that set data into array.

Then I create an if statement in the for loop statement to check if it matches then, store the data entered in a variable and display it in the end. I'll give you an example code

public static void main (String [] args)
{
    TestClass [] emp = new testclass [3];

    String name, id, nickname;
    int sameName = 0;

    for (int i = 0; i < 3; i++)
    {
        emp[i] = new testclass();

        name = JOptionPane.showInputDialog ("Your name");
        id = JOptionPane.showInputDialog ("Your ID");
        nickname = JOptionPane.showInputDialog ("Your Nickname");

        emp[i].setTestClass (name, id, nickname);

        System.out.println (emp[i]);

        if ("David".equalsIgnoreCase(emp[i].getName()) && "Dave".equalsIgnoreCase(emp[i].getNickname()))
        {
            sameName = i;
        }
    }

    System.out.println ("People with the same name and nickname : \n\n" + emp[sameName]) //Is this the correct way?
}

So as you notice the program will first display out all 3 input,

then display out output "people with the same name & nickname".

So assume, there are two persons with same name and nickname.

How do you make it possible to print the data stored at the end after all 3 input displayed out?

Answer 1

You cannot do that with single variable for index, as there could be many users matching your criteria. There are many ways to handle that. The simplest would be to:

before for loop create any container, eg

List<TestClass> matching = new ArrayList<TestClass>();

inside for loop, if particular item is matching your criterias, just add it to the collection:

matching.add(emp[i])

after for loop you have references to all items matching you criterias, so you can do whatever you want with them. Just printing for example:

for(final TestClass item : matching) {
   System.out.println ("Another person matching was: " + item.getName());
}

best regards,

Darek

Answer 2

You will have to store the indizes or something similar, that have the same name. Making it simple just with arrays it would something like this:

boolean[] sameName = new boolean[emp.length];
...

// in the loop the if statement:
if ("David".equalsIgnoreCase(emp[i].getName()) && "Dave".equalsIgnoreCase(emp[i].getNickname()))
{
    sameName[i] = true;
}
else
{
    sameName[i] = false;
}    
...

// the output part:
System.out.println ("People with the same name and nickname : \n");
for (int i = 0; i < emp.length; i++) {
    if(sameName[i])
        System.out.println(emp[i]);
}

Answer 3

You could store the Dave/David duplicate's indexes and that print them.

A quick and dirty way could be this

String indexes = "";
for (int i = 0; i < 3; i++)
    {
        emp[i] = new testclass();

        name = JOptionPane.showInputDialog ("Your name");
        id = JOptionPane.showInputDialog ("Your ID");
        nickname = JOptionPane.showInputDialog ("Your Nickname");

        emp[i].setTestClass (name, id, nickname);

        System.out.println (emp[i]);

        if ("David".equalsIgnoreCase(emp[i].getName() && "Dave".equalsIgnoreCase(emp[i].getNickname()))
        {
            indexes += i.toString();
        }
    }
System.out.println ("People with the same name and nickname : \n");
for (int j = 0; j < indexes.length(); j+=1) {
    int index = Integer.parseInt( indexes.charAt(j) );
    System.out.println(emp[j]);
}