获取数组的和与平均

Question

我正在为课堂做一个程序。到目前为止，我已经完成了1-3个，但我不知道如何实现4和5个。我已经被困在这上面一段时间了。必须使用两个类。

null

package Hw2;
import java.util.Scanner;
import java.util.ArrayList;

public class BankArrayTester {
public static void main(String[] args){
      Scanner in = new Scanner(System.in);
      System.out.println("Please enter the number bank accounts:");
      int accounts= in.nextInt();
      BankAccount [] accountinfo = new BankAccount [accounts];
      int c=0;
      while(c<accounts){
          c++;
         System.out.println("Enter account number for account "+c);
        int number=in.nextInt();
        System.out.println("Enter balance for account "+c);
        double balance=in.nextDouble();
        int a=0;
        BankAccount numberbalance = new BankAccount(number,balance);
        accountinfo [a]=numberbalance;
        double test1;
        for (int i = 0; i < accountinfo.length; i++) {
            test1 = accountinfo[a].getBalance(); 
            System.out.println(test1);
        }
      }
    }
}

其他类

    package Hw2;
     /**
     A bank account has a balance that can be changed by 
   deposits and withdrawals.
  */
  public class BankAccount
  {
    private double balance;
    private int accountNumber;

/**
   Constructs a bank account with a zero balance.
*/
public BankAccount(int _accountNumber)
{   
   balance = 0;
}

/**
   Constructs a bank account with a given balance.
   @param initialBalance the initial balance
*/
public BankAccount(int _accountNumber, double initialBalance)
{   
   accountNumber = _accountNumber;
   balance = initialBalance;
}

/**
   Deposits money into the bank account.
   @param amount the amount to deposit
*/
public void deposit(double amount)
{  
   double newBalance = balance + amount;
   balance = newBalance;
}

/**
   Withdraws money from the bank account.
   @param amount the amount to withdraw
*/
public void withdraw(double amount)
{   
   double newBalance = balance - amount;
   balance = newBalance;
}

/**
   Gets the current balance of the bank account.
   @return the current balance
*/
public double getBalance()
{   
   return balance;
}
}

/**
   Gets the account number of the bank account.
   @return the account number
*/

Answer 1

使用以下方法查找余额的总和

double sum=0;
for (int i = 0; i < accountinfo.length; i++) {
        test1 = accountinfo[i].getBalance(); 
        sum+=test1;
        System.out.println(test1);
    }

打印总和和平均数

System.out.println("Total ::"+sum);
System.out.println("Average ::"+sum/accounts);