How to get an array of class references to another method

Question

i am a student that learning java

This time, I'm making a code for recommending a prize as a school assignment.

Sorry for the inconvenience because it's Google Translate

I would like to ask you how to get the class referenced array into another method.

In the code below, if the Customer[] a array created in CustomerGenerator is checked in the Run method, the value is not saved and output.

thank you for your help

package assignment_1;

import java.util.InputMismatchException;
import java.util.Scanner;

public class LotteryApp {
    private static Scanner scanner;
    
    public LotteryApp() {
        scanner = new Scanner(System.in);   
    }
        
    public void GoodGenerator(Good[] b) {
        int nGoods;
        
        while(true) {
            
            System.out.print("게임의 당첨 경품은 몇개입니까>>");
            
            try {
                nGoods = scanner.nextInt();
                break;
            } 
            
            catch(InputMismatchException e) {
                System.out.println("정수를 입력해야만 합니다.");
                scanner.nextLine(); // <Enter> 키까지 읽어서 버린다.
                continue;
            }
            
        }
        
        b = new Good[nGoods]; // Player [] 레퍼런스 배열 생성
        
        // 각 참여자의 이름을 입력받아 Player 객체 생성
        for(int i=0; i<nGoods; i++) {
            System.out.print("경품의 이름을 입력하세요>>");
            String name = scanner.next();
            b[i] = new Good(name);
        }
    
    }
    
    static void CustomerGenerator(Customer[] a) {
        
        int nPlayers;
        
        while(true) {
            
            System.out.print("게임에 참가하는 인원은 몇명입니까>>");
            
            try {
                nPlayers = scanner.nextInt();
                break;
            } 
            
            catch(InputMismatchException e) {
                System.out.println("정수를 입력해야만 합니다.");
                scanner.nextLine(); // <Enter> 키까지 읽어서 버린다.
                continue;
            }
            
        }
        
        a = new Customer[nPlayers]; // Player [] 레퍼런스 배열 생성
        
        // 각 참여자의 이름을 입력받아 Player 객체 생성
        for(int i=0; i<nPlayers; i++) {
            System.out.print("참가자의 이름을 입력하세요>>");
            String name = scanner.next();
            a[i] = new Customer(name);
        }

        
        

    }
    
    public void run() {
        int Whack;
        Customer[] a = {};
        Good[] b = {};
        while(true) {
            
            System.out.print("게임에 꽝은 몇개입니까>>");
            
            try {
                Whack = scanner.nextInt();
                break;
            } 
            
            catch(InputMismatchException e) {
                System.out.println("정수를 입력해야만 합니다.");
                scanner.nextLine(); // <Enter> 키까지 읽어서 버린다.
                continue;
            }
            
        }
        
        CustomerGenerator(a);
        GoodGenerator(b);
        
        System.out.println(a[0].CustomerName);

        int A = a.length;
        System.out.println(A);

        
        
        
        
    }
    
    public static void main(String[] args) {
        LotteryApp game = new LotteryApp();
        game.run();
    }
}




class Good{
    private Scanner scanner;
    public String GoodName;
    public int GoodPrice;
    public boolean GoodUse;
    
    public Good(String GoodName) {
        this.GoodName = GoodName;
        scanner = new Scanner(System.in);
    }
}


class Customer{
    private Scanner scanner;
    public String CustomerName;
    public String WinningPriceName;
    public boolean Winning;
    
    public Customer(String CustomerName) {
        this.CustomerName = CustomerName;
        scanner = new Scanner(System.in);   
    }
}

Answer 1

Think of a function parameter like a local variable of that function:
You can put a value in it from inside the function, but it will not go outside.

You have to return the array you allocate from CustomerGenerator like this:

static Customer [] CustomerGenerator() {

    /** skip same code **/
    Customer [] outArray = new Customer[nPlayers]; // Player [] 레퍼런스 배열 생성
    
    // 각 참여자의 이름을 입력받아 Player 객체 생성
    for(int i=0; i<nPlayers; i++) {
        System.out.print("참가자의 이름을 입력하세요>>");
        String name = scanner.next();
        outArray[i] = new Customer(name);
    }

    return outArray;
}