9-weeks

BankAccount

import java.util.Scanner;

public class BankAccount{
	private double balance;
	
	public BankAccount(double initialBalance){
		if(initialBalance > 0.0)
			balance = initialBalance;
	}
	public void credit(double amount){
		balance += amount;
	}
	public double getBalance(){
		return balance;
	}
	public static void main(String[] args){
		BankAccount account1 = new BankAccount(50.00);
		BankAccount account2 = new BankAccount(-7.53);
		
		System.out.printf("account1 balance: $%.2f\n", account1.getBalance());
		System.out.printf("account2 balance: $%.2f\n", account2.getBalance());
		
		Scanner input = new Scanner(System.in);
		double depositAmount;
		
		System.out.print("Enter deposit amount: ");
		depositAmount = input.nextDouble();
		account1.credit(depositAmount);
		System.out.printf("account1 balance: $%.2f\n\n", account1.getBalance());
		
		System.out.print("Enter deposit amount: ");
		depositAmount = input.nextDouble();
		account2.credit(depositAmount);
		System.out.printf("account2 balance: $%.2f\n\n" , account2.getBalance());
		input.close();
	}
}

Circle

public class Circle{
	int radius;
	String name;
	
	public Circle(){} // 기본 생성자라서 없어도 무방하다.
		
	public double getArea(){
		return 3.14*Math.pow(radius, 2);
	}
	public static void main(String[] args){
		Circle pizza;
		pizza = new Circle();
		pizza.radius = 10;
		pizza.name = "Java-pizza";
		double area = pizza.getArea();
		System.out.println("Area of: " + pizza.name + " " + area);
		
		Circle donut = new Circle();
		donut.radius = 2;
		donut.name = "Java-donut";
		area = donut.getArea();
		System.out.println("Area of: " + donut.name +" " + area);
	}
}

RandomIntegers

import java.util.Random;

public class RandomIntegers{
	public static void main(String[] args){
		Random randomNumbers = new Random();
		int face;
		
		for(int count=1; count<=20; count++) {
			face = 1+randomNumbers.nextInt(6);
			System.out.printf("%d ", face);
		}
	}
}

Rectangle

import java.util.Scanner;

public class Rectangle{
	int width;
	int height;
	
	public int getArea(){
		return width*height;
	}
	public static void main(String[] args){
		Rectangle rect = new Rectangle();
		Scanner scanner = new Scanner(System.in);
		System.out.print(">> ");
		rect.width = scanner.nextInt();
		rect.height = scanner.nextInt();
		System.out.println("Area: " + rect.getArea());
		scanner.close();
	}
}