在Java程序中，如何讓賬號和余額結合呢？這需要通過定義一個新的類來實現。

首先，在類中定義賬戶和余額的兩個私有變量：

public class BankAccount {
private String accountNumber;
private double balance;
}

然后，在類的構造函數中初始化這兩個變量：

public BankAccount(String accountNumber, double balance) {
this.accountNumber = accountNumber;
this.balance = balance;
}

接下來，可以添加一些簡單的方法來操作賬戶和余額：

public String getAccountNumber() {
return accountNumber;
}
public void setAccountNumber(String accountNumber) {
this.accountNumber = accountNumber;
}
public double getBalance() {
return balance;
}
public void setBalance(double balance) {
this.balance = balance;
}
public void deposit(double amount) {
balance += amount;
}
public void withdraw(double amount) {
balance -= amount;
}

現在，賬號和余額已經結合在一起了。可以通過實例化一個新的BankAccount對象來訪問它們：

BankAccount myAccount = new BankAccount("1234567890", 1000.00);
System.out.println("My account number is " + myAccount.getAccountNumber());
System.out.println("My balance is " + myAccount.getBalance());
myAccount.deposit(500.00);
System.out.println("My balance after deposit is " + myAccount.getBalance());
myAccount.withdraw(200.00);
System.out.println("My balance after withdrawal is " + myAccount.getBalance());

通過上述代碼，我們可以看到如何定義一個新的類，并在其中結合賬號和余額。