Account class with a double instance variable balance and a constructor and deposit method that perform validation. - Java Object Oriented Design

Java examples for Object Oriented Design:Field

  1. HOME
  2. Java
  3. Object Oriented Design
  4. Field

Introduction

Inputting and outputting floating-point numbers with Account objects.

Demo Code

import java.util.Scanner;

public class Main
{
   public static void main(String[] args) 
   {/*  w w w . j av  a2 s  .c  o m*/
      Account account1 = new Account("James Bond", 50.00);
      Account account2 = new Account("Michael Bates", -7.53); 

      // display initial balance of each object
      System.out.printf("%s balance: $%.2f%n",
         account1.getName(), account1.getBalance()); 
      System.out.printf("%s balance: $%.2f%n%n",
         account2.getName(), account2.getBalance()); 

      // create a Scanner to obtain input from the command window
      Scanner input = new Scanner(System.in);

      System.out.print("Enter deposit amount for account1: "); // prompt
      double depositAmount = input.nextDouble(); // obtain user input
      System.out.printf("%nadding %.2f to account1 balance%n%n", 
         depositAmount);
      account1.deposit(depositAmount); // add to account1's balance

      // display balances
      System.out.printf("%s balance: $%.2f%n",
         account1.getName(), account1.getBalance()); 
      System.out.printf("%s balance: $%.2f%n%n",
         account2.getName(), account2.getBalance()); 

      System.out.print("Enter deposit amount for account2: "); // prompt
      depositAmount = input.nextDouble(); // obtain user input
      System.out.printf("%nadding %.2f to account2 balance%n%n", 
         depositAmount);
      account2.deposit(depositAmount); // add to account2 balance

      // display balances
      System.out.printf("%s balance: $%.2f%n", 
         account1.getName(), account1.getBalance()); 
      System.out.printf("%s balance: $%.2f%n%n",
         account2.getName(), account2.getBalance()); 
   } 
}
class Account
{   
   private String name; // instance variable 
   private double balance; // instance variable 

   // Account constructor that receives two parameters  
   public Account(String name, double balance) 
   {
      this.name = name; // assign name to instance variable name

      // validate that the balance is greater than 0.0; if it's not,
      // instance variable balance keeps its default initial value of 0.0
      if (balance > 0.0) // if the balance is valid
         this.balance = balance; // assign it to instance variable balance
   }

   // method that deposits (adds) only a valid amount to the balance
   public void deposit(double depositAmount) 
   {      
      if (depositAmount > 0.0) // if the depositAmount is valid
         balance = balance + depositAmount; // add it to the balance 
   }

   // method returns the account balance
   public double getBalance()
   {
      return balance; 
   } 

   // method that sets the name
   public void setName(String name)
   {
      this.name = name; 
   } 

   // method that returns the name
   public String getName()
   {
      return name; 
   } 
}

Result


Related Tutorials