bank.java

来自「《Java数据结构和算法》这本经典书的书上的源程序」· Java 代码 · 共 46 行

// bank.java
// demonstrates basic OOP syntax
// to run this program: C>java BankApp
////////////////////////////////////////////////////////////////
class BankAccount
   {
   private double balance;                   // account balance

   public BankAccount(double openingBalance) // constructor
      {
      balance = openingBalance;
      }

   public void deposit(double amount)        // makes deposit
      {
      balance = balance + amount;
      }

   public void withdraw(double amount)       // makes withdrawal
      {
      balance = balance - amount;
      }

   public void display()                     // displays balance
      {
      System.out.println("balance=" + balance);
      }
   }  // end class BankAccount
////////////////////////////////////////////////////////////////
class BankApp
   {
   public static void main(String[] args)
      {
      BankAccount ba1 = new BankAccount(100.00); // create acct

      System.out.print("Before transactions, ");
      ba1.display();                         // display balance

      ba1.deposit(74.35);                    // make deposit
      ba1.withdraw(20.00);                   // make withdrawal

      System.out.print("After transactions, ");
      ba1.display();                         // display balance
      }  // end main()
   }  // end class BankApp