/* To do: * - Allow user to use the below functions to add name and coin to populate the array addItemToArray(); * - Checks array for same name and updates coin value test2.addCoin()

* * Current errors: * - Exception in thread "main" java.lang.NullPointerException: Cannot read the array length because "test1.coin" is null */

test1

import java.util.Scanner;  public class test1 {    private static test2[] coin;    public static void main(String[] args) {    addToArray();  addItemToArray();    }    private static void addToArray() {  test2[] coin2 = new test2[coin.length + 1];  System.arraycopy(coin, 0, coin2, 0, 0);  coin = coin2;  }        private static void addItemToArray() {  Scanner input = new Scanner(System.in);  test2[] coin = new test2[0];     while(true) {  System.out.println("Add user? 1. Yes  2. No");  int choice = input.nextInt();    if(choice == 1) {  for(int i = 0; i <= coin.length; i++) {  System.out.println("Enter name: ");  String name = input.nextLine();  System.out.println("Enter change: ");  int cash = input.nextInt();    // checks for existing user and updates  for(int j = 0; j < coin.length; j++) {  if(coin[j].getName().equals(name)) {  test2 change = new test2();  test2.addCoin(cash);  coin[j] = change;  break;  }  }    addToArray();    coin[i].setName(name);  coin[i].setCoin(cash);    System.out.println("Add more? 1. Yes 2. No");  choice = input.nextInt();  if(choice == 2) {  break;  }  }  }if(choice == 2){  break;  }  }  }  }

test2

 public class test2 {    private String name;  private int coin;    public test2() {  this.name = "no name";  this.coin = 0;  }    public test2(String name, int coin) {  this.name = name;  this.coin = coin;  }    public void addCoin(int cash) {  this.coin +=cash;    }    public String getName() {  return name;  }    public void setName(String name) {  this.name = name;  }    public int getCoin() {  return coin;  }    public void setCoin(int coin) {  this.coin = coin;  }    }