Is it possible to declare reference variables in for or while loop?

Question

I wrote a short code that declares 6 reference variables from a class named 'ChosenCompanies' to practice classes and constructors in Java.

It is the following:

public static void main(String[] args) {

    String[] FinalCompaniesName = new String[6];

    ChosenCompanies com1 = new ChosenCompanies();
    ChosenCompanies com2 = new ChosenCompanies();
    ChosenCompanies com3 = new ChosenCompanies();
    ChosenCompanies com4 = new ChosenCompanies();
    ChosenCompanies com5 = new ChosenCompanies();
    ChosenCompanies com6 = new ChosenCompanies();

    Scanner scanner = new Scanner(System.in);
    int choice;
    int count = 1;
    while(count <= 2) {
        switch(count) {
        case 1:
            System.out.println("Choose one:");
            System.out.println("1. " + com1.name);
            System.out.println("2. " + com2.name);
            System.out.println("3. " + com3.name);
            choice = scanner.nextInt();
            switch(choice) {
            case 1:
                FinalCompaniesName[0] = com1.name;
                break;
            case 2:
                FinalCompaniesName[0] = com2.name;
                break;
            case 3:
                FinalCompaniesName[0] = com3.name;
                break;
            }
        break;
        case 2:
            System.out.println("Choose one:");
            System.out.println("1. " + com4.name);
            System.out.println("2. " + com5.name);
            System.out.println("3. " + com6.name);
            choice = scanner.nextInt();
            switch(choice) {
            case 1:
                FinalCompaniesName[1] = com4.name;
                break;
            case 2:
                FinalCompaniesName[1] = com5.name;
                break;
            case 3:
                FinalCompaniesName[1] = com6.name;
                break;
            }
            break;
        }    
        count++;
    }
        System.out.println("You have chosen: "
 + FinalCompaniesName[0] + ", " + FinalCompaniesName[1]);

}

As you can see from the above code, these two parts are almost the same except for the names of reference variables(com1, com2, com3, com4...):

part 1:

        switch(count) {
        case 1:
            System.out.println("Choose one:");
            System.out.println("1. " + com1.name);
            System.out.println("2. " + com2.name);
            System.out.println("3. " + com3.name);
            choice = scanner.nextInt();
            switch(choice) {
            case 1:
                FinalCompaniesName[0] = com1.name;
                break;
            case 2:
                FinalCompaniesName[0] = com2.name;
                break;
            case 3:
                FinalCompaniesName[0] = com3.name;
                break;
            }
         break;

part 2:

        case 2:
            System.out.println("Choose one:");
            System.out.println("1. " + com4.name);
            System.out.println("2. " + com5.name);
            System.out.println("3. " + com6.name);
            choice = scanner.nextInt();
            switch(choice) {
            case 1:
                FinalCompaniesName[1] = com4.name;
                break;
            case 2:
                FinalCompaniesName[1] = com5.name;
                break;
            case 3:
                FinalCompaniesName[1] = com6.name;
                break;
                }
            break;
        }    

I am wondering if I can minimize the amount of the code above by using a for or while loop, since the name of the reference variables are increased by 1, like integer 'i' in a common for statement.

In short, is it possible to declare reference variables by using loop?

Answer 1

It is not possible in Java to create dynamic variables (but with reflections, see here)

You can create an array and use the i as index like chosenCompanies[i].

Otherwise you can use lists or maps.

Edit:

That would e.g. look like this. Apart from the sence of the code, this example shows only how you would use an array:

    String[] choosenCompanieNames = new String[2]; // you only store two values, not 6 values

    //lets store the values to chose in arrays
    String[] possibleCompanieNames = new String[6]; // 6 possible values to choose (com1 - com6)
    possibleCompanieNames[0] = "com1";
    possibleCompanieNames[1] = "com2";
    possibleCompanieNames[2] = "com3";
    possibleCompanieNames[3] = "com4";
    possibleCompanieNames[4] = "com5";
    possibleCompanieNames[5] = "com6";

    //I deleted the while loop, as it only has two ways and every way has its own code. 

    Scanner scanner = new Scanner(System.in);
    int choice;

    System.out.println("Choose one:");
    System.out.println("1. " + possibleCompanieNames[0]);
    System.out.println("2. " + possibleCompanieNames[1]);
    System.out.println("3. " + possibleCompanieNames[2]);
    choice = scanner.nextInt();
    choosenCompanieNames[0] = possibleCompanieNames[choice-1]; //you must subtract one, as the array index starts at 0 and ends on 5

    System.out.println("Choose one:");
    System.out.println("1. " + possibleCompanieNames[3]);
    System.out.println("2. " + possibleCompanieNames[4]);
    System.out.println("3. " + possibleCompanieNames[5]);
    choice = scanner.nextInt();
    choosenCompanieNames[1] = possibleCompanieNames[3+choice-1]; //here you want com4, com5 and com6, so you can e.g. add 3 to index and substract one like code above. Or better add only 2, as 3-1=2


    System.out.println("You have chosen: "
         + choosenCompanieNames[0] + ", " + choosenCompanieNames[1]);

Answer 2

Your example is confusing so I don't know what exactly are you trying to accomplish, but here is an example of how to prompt the user to select a new name for each company from a list of existing company names:

    public class Company {

    /**
     * Array of available company names used to construct
     * initial companies. These names are also used as possible
     * choices when changing company names through {@link #changeCompanyNames()}
     */
    private static final String[] COMPANY_NAMES = new String[]
            { "Alphabet", "Microsoft", "IBM", "Amazon", "Oracle", "Apple" };

    /**
     * <p>
     * Array of Company objects initialized with a fixed number of
     * new companies equal to the number of String entries in {@link #COMPANY_NAMES}.
     * </p><p>
     * Each company entry will inheriting a name from the mentioned array
     * in the initialization process done in {@link #initializeCompanies()}
     * </p>
     */
    public static final Company[] COMPANIES = initializeCompanies();

    private String name;

    /**
     * Internal constructor with private access to
     * prevent class construction outside this class
     */
    private Company(String name) {
        this.name = name;
    }

    /**
     * Should only be used internally on class loading to
     * construct an array of companies from a list of company names.
     */
    private static Company[] initializeCompanies() {

        Company[] companies = new Company[COMPANY_NAMES.length];
        for (int i = 0; i < COMPANY_NAMES.length; i++) {
            companies[i] = new Company(COMPANY_NAMES[i]);
        }
        return companies;
    }

    /**
     * Change any or all company names by prompting the user to choose
     * a new name for each company from the list of available companies.
     */
    public static void changeCompanyNames() {

        java.util.Scanner scanner = new java.util.Scanner(System.in);
        /*
         * Create a new array of company names that is identical to the existing
         * array of company names. We will change names here on user input and
         * then update each new company name to values from this array.
         */
        final String[] finalCompanyNames = COMPANY_NAMES.clone();
        /*
         * Iterate through an array of companies with a for-loop
         * accessing and processing each company entry
         */
        for (int i1 = 0; i1 < COMPANIES.length; i1++)
        {
            /* Prompt the user to choose a new company name for the
             * company at index i1 from COMPANIES array.
             */
            System.out.printf("Choose a new company name for %s company:%n", COMPANIES[i1].name);
            /*
             * Again iterate through all companies and print their names to
             * console offering the user a list of possible names to choose from
             */
            for (int i2 = 0; i2 < COMPANIES.length; i2++) {
                System.out.printf("%d. %s%n", i2 + 1, COMPANIES[i2].name);
            }
            /*
             * Get user input and validate it, then either update the array of
             * final names with the new entry or print an error and move the index
             * to the previous position if the input was an invalid number
             */
            int input = scanner.nextInt();
            if (input > 0 && input <= COMPANIES.length) {
                finalCompanyNames[i1] = COMPANY_NAMES[input - 1];
                System.out.println("You have choosen company name " + finalCompanyNames[i1]);
            }
            else {
                System.out.printf("Error: input is not in range (1-%d)%n", COMPANIES.length);
                /*
                 * It's imperative that we move the index to the previous
                 * position so we can iterate over this company entry again
                 */
                i1 -= 1;
            }
        }
        // Print simple line separator
        System.out.println("");

        /* Print each choosen name that is different then the original
         * company name and update the appropriate company name field value
         */
        for (int i = 0; i < finalCompanyNames.length; i++)
        {
            if (!finalCompanyNames[i].equals(COMPANY_NAMES[i])) {
                System.out.printf("Company %s has changed name to %s%n", COMPANY_NAMES[i], finalCompanyNames[i]);
                COMPANIES[i].name = finalCompanyNames[i];
            }
        }
    }
}

Example console output after the user is done choosing:

Company Alphabet has changed name to IBM
Company Microsoft has changed name to Amazon
Company IBM has changed name to Alphabet
Company Amazon has changed name to Oracle
Company Oracle has changed name to Microsoft
Company Apple has changed name to Amazon

Here we are able to set any number of companies and let the user choose any of the offered names for them. The code might look a tad bit daunting for a beginner but this is actually the simplest way of doing this without involving any of the more complex Java concepts into play.

Feel free to ask any questions regarding this implementation. I will be quite happy to help out.

EDIT: Updated the code to include detailed comments and a more comprehensive structure that is easier to understand and fixed an indexing issue.