1 // A class with data for a savings account. 2 // This first example illustrates how to define a class with non-public 3 // instance variables and some public methods. 4 // Nancy McCracken 3/14/97 5 // API of this class: 6 // 7 // public class Account 8 // { 9 // public Account (String n, double b) 10 // public String getname() 11 // public double getbalance() 12 // public int getbalancedollars() 13 // public int getbalancecents() 14 // public void withdraw (double amount) 15 // public void deposit (double amount) 16 // public double monthactivity () 17 // } 18 19 public class Account 20 { // instance variables 21 String name; 22 double balance; 23 static double interestrate = .04; 24 25 // constructor method is used to initialize instance variables 26 public Account (String n, double b) 27 { name = n; 28 balance = b; 29 } 30 31 // accessor methods 32 public String getname() 33 { return name; } 34 35 public double getbalance() 36 { return balance; } 37 38 public int getbalancedollars() 39 { return (int)Math.floor(balance); } 40 41 public int getbalancecents() 42 { return (int)(balance - Math.floor(balance))*100 ; } 43 44 // other methods 45 public void withdraw (double amount) 46 { 47 if ((balance - amount) > 0) 48 { balance -= amount; 49 } 50 else { } // later will return exception "insufficient funds" 51 } 52 53 public void deposit (double amount) 54 { balance += amount; } 55 56 // returns monthly interest and updates balance 57 public double monthactivity() 58 { double interest = (balance * interestrate)/12; 59 balance += interest; 60 return interest; 61 } 62 }