조건문 복습

import java.util.Scanner;
//나이를 입력받아 20대인지 판별하는 프로그램을 만들어라 if else사용(1~99)
public class Jogun {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("나이를 입력하세요");
		int age = scanner.nextInt();
		
		if((30>age)&&(age>19)) {
		System.out.println("20대 입니다.");
		} else {
			System.out.println("20대가 아닙니다.");
		}
		scanner.close();
	}

}

성적산출(다중 if else)

import java.util.Scanner;
public class If_else {

	public static void main(String[] args) {
//		다중 if else를 사용하여 성적을 산출하세요. 
		Scanner scanner = new Scanner(System.in);
		System.out.println("성적을 입력하세요");
		
		int score = scanner.nextInt();
		
		if(score>=90) {
			if(score>=95) {
				System.out.println("A+");
			} else {
				System.out.println("A");
			}
		}
		else if(score>=80) {
			if(score>=85) {
				System.out.println("B+");
			} else {
				System.out.println("B");
			}
		}
		else if(score>=70) {
			if(score>=75) {
				System.out.println("c+");
			} else {
				System.out.println("c");
			}
		}
		else if(score>=60) {
			if(score>=65) {
				System.out.println("d+");
			} else {
				System.out.println("d");
			}
		} else {
			System.out.println("f");
		}
	}

}

동전 개수 구하기 문제(p.88-6)

import java.util.Scanner;
public class P88_6 {

	public static void main(String[] args) {
		System.out.println("돈을 입력하세요");
		Scanner scanner = new Scanner(System.in);
		int money = scanner.nextInt();
		 
		System.out.println("오만원권 "+money/50000+"개 ");
		money = money%50000;
		
		System.out.println("만원 권 "+money/10000+"개 ");
		money = money%10000;
		
		System.out.println("천원 권 "+money/1000+"개 ");
		money = money%1000;
		
		System.out.println("오백원 "+money/500+"개 ");
		money = money%500;
		
		System.out.println("백원 "+money/100+"개");
		money = money%100;
		
		System.out.println("십원 "+money/10+"개");
		money= money%10;
		
		System.out.println("일원 "+money/1+"개");
		money = money%1;
		
	}
}

p.88-7

import java.util.Scanner;
public class P88_7 {

	public static void main(String[] args) {
		System.out.println("성적을 입력하세요");
		Scanner scanner = new Scanner(System.in);
		char score = scanner.next().charAt(0);
		
		switch(score) {
		case 'A':
		case 'B':
			System.out.println("Excellent");
			break;
			
		case 'C':
		case 'D':
			System.out.println("Good");
			break;
			
		case 'F':
			System.out.println("Bye");
			break;
			
		default :
			System.out.println("다시입력해주세요");
		}
	}

}

p.88 - 8

import java.util.Scanner;
public class P88_8 {

	public static void main(String[] args) {
		System.out.println("커피를 주문하세요");
		Scanner scanner = new Scanner(System.in);
		String menu = scanner.next();
		int num = scanner.nextInt();
		
		if(menu.equals("에스프레소")) {
			int price = num * 2000;
			System.out.println(price+"원입니다");
		}
		else if(menu.equals("아메리카노")) {
			int price = num *2500;
			System.out.println(price+"원입니다");
		}
		else if(menu.equals("카푸치노")) {
			int price = num *3000;
			System.out.println(price+"원입니다");
		}
		else if(menu.equals("카페라테")) {
			int price = num *3500;
			System.out.println(price+"원입니다");
		}
		
		scanner.close();
	}

}

import java.util.Scanner;
public class P88_8switch {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("커피 주문하세요");
		String coffee = scanner.next();
		int num = scanner.nextInt();
		
		switch(coffee) {
		case "아메리카노":
		int price = num * 2500;
		System.out.println(price+"원입니다");
		break;
		
		case "카푸치노":
	    price = num * 3000;
		System.out.println(price+"원입니다");
		break;
		
		case "에스프레소":
		price = num * 2000;
		System.out.println(price+"원입니다");
		break;
		
		case "카페라테":
		price = num * 3500;
		System.out.println(price+"원입니다");
		break;
		
		default:
			System.out.println("다시 입력해주세요");
		
		}
	}

}

369

import java.util.Scanner;
public class P88_9 {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("1~99정수를 입력하세요");
		int num = scanner.nextInt();
		int first = num/10;
		int second = num%10;
		
		if(first%3==0){
		 if(second%3==0) {
			 System.out.println("박수짝짝");
		 }else {
			 System.out.println("박수짝");
		 }
		}
		else if (second%3==0) {
			System.out.println("박수짝");
		} else {
			System.out.println("박수없음");
		 }
		scanner.close();
		}
	
	}

커피 응용문제(10)

import java.util.Scanner;
public class P88_10 {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		System.out.println("커피 주문하세요");
		
		String coffee=scanner.next();
		int num = scanner.nextInt();
		
		if(coffee.equals("에스프레소")) {
			if(num>=10){
				int price=num*1900;
				System.out.println(price+"입니다.");		
			} else {
				int price = num * 2000;
				System.out.println(price+"입니다.");		
			}
		} 
		else if(coffee.equals("아메리카노")) {
			int price = num * 2500;
			System.out.println(price+"입니다.");	
		}
		else if(coffee.equals("카푸치노")) {
			int price = num * 3000;
			System.out.println(price+"입니다.");
	}
		else if(coffee.equals("카페라테")) {
			int price = num * 3500;
			System.out.println(price+"입니다.");
		}
		scanner.close();
	}

}

while

1부터 10까지 출력

package ch03;
//while문을 사용하여 1~10까지 화면에 출력하는 프로그램 작성하세요
public class While1 {
	
	public static void main(String[] args) {
	int num=1;	
	while(num<11) {
		System.out.print(num);
		num++;
	 }
  }

}

1부터 10까지 합

//		1부터 10까지의 합
		int i = 1;
		int sum=0;
		while(i<11) {
			sum = sum+i;
			i++;
		}
		System.out.println("합계: "+sum);
  }