====== Ch.05 제어문 ======

===== 조건문 =====

==== if문 ====
<code java>
package chapter05;

public class IfEx {

	public static void main(String[] args) {
		
		int score = 70;
		
		System.out.println("시험 시작");
		if (score >= 60) {
			System.out.println("합격입니다.");
		}
		System.out.println("시험 끝");

	}

}

</code>

====if else문====

<code java>
package chapter05;

public class IfEx1 {

	public static void main(String[] args) {
		
		int score = 50;
		
		System.out.println("시험 시작");
		if (score >= 60) {
			System.out.println("합격입니다.");
		} else {
			System.out.println("불합격입니다.");
		}
		System.out.println("시험 끝");

	}

}

</code>

====if ~else if====

<code java>
package chapter05;

public class IfEx2 {

	public static void main(String[] args) {
		
		int score = 80;
		String grade = "";
		
		System.out.println("학점부여 시작");
		if (score >= 95) {
			grade = "A+";
		} else if (score >= 90){
			grade = "A";
		} else if (score >= 85) {
			grade = "B+";
		} else if (score >= 80) {
			grade = "B";
		} else if (score >= 70) {
			grade = "C";
		} else if (score >= 60) {
			grade = "D";
		} else {
			grade = "F";
		}
		System.out.println("당신의 학점은 "+grade+"입니다.");
		System.out.println("학점부여 끝");

	}

}
</code>

====중첩 if문====

<code java>
package chapter05;

public class IfEx3 {

	public static void main(String[] args) {
		
		int math = 90;
		int eng = 95;
		
		if (math >= 60) {
			if (eng >= 60) {
				System.out.println("통과");
			}
		} else {
			System.out.println("탈락");
		}

	}

}

</code>

<code java>
package chapter05;

public class IfEx4 {

	public static void main(String[] args) {
		
		int math = 90;
		int eng = 95;
		
		if (math >= 60 && eng >= 60) {
			System.out.println("통과");
		} else {
			System.out.println("탈락");
		}

	}

}

</code>

====switch문====

<code java>
package chapter05;

import java.util.Scanner;

public class SwitchEx {

	public static void main(String[] args) {
		
		System.out.println("점수를 입력하세요.");
		Scanner scan = new Scanner(System.in);
		
		int score = scan.nextInt();
		String grade = "";
		switch(score / 10) {
			case 9:
				grade = "A";
				break;
			case 8:
				grade = "B";
				break;
			case 7:
				grade = "C";
				break;
			case 6:
				grade = "D";
				break;
			default:
				grade = "F";
		}
		System.out.println("학점 : "+grade);

	}

}

</code>

<code java>
package chapter05;

import java.util.Scanner;

public class SwitchEx {

	public static void main(String[] args) {
		
		System.out.println("점수를 입력하세요.");
		Scanner scan = new Scanner(System.in);
		
		int score = scan.nextInt();
		String grade = "";
		switch(score / 10) {
			case 9:
				grade = "A";
				break;
			case 8:
				grade = "B";
				break;
			case 7:
				grade = "C";
				break;
			case 6:
				grade = "D";
				break;
			default:
				grade = "F";
		}
		System.out.println("학점 : "+grade);

	}

}

</code>
==break의 사용==
<code java>
package chapter05;

public class SwitchEx2 {

	public static void main(String[] args) {
		
		int number = 3;
		
		switch(number) {
			case 1:
				System.out.println("1번");
				break;
			case 2:
				System.out.println("2번");
				break;
			case 3:
				System.out.println("3번");
				break;
			case 4:
				System.out.println("4번");
				break;
			case 5:
				System.out.println("5번");
				break;
			default:
				System.out.println("6번");
		}

	}

}

</code>

=====반복문=====

====for문====

<code java>
package chapter05;

public class ForEx {

	public static void main(String[] args) {
		
		for (int i=0; i<10; i++) {
			System.out.println("i = "+i);
		}

	}

}

</code>

<code java>
package chapter05;

public class ForEx2 {

	public static void main(String[] args) {
		
		int sum = 0;
		
		for (int i=1; i<=100; i++) {
			sum += i;
		}
		
		System.out.println("합계 : "+sum);

	}

}

</code>

====while문====

<code java>
package chapter05;

public class WhileEx {

	public static void main(String[] args) {
		
		int sum = 0;
		int i = 1;
		
		while (i <= 100) {
			sum += i;
			i++;
		}
		
		System.out.println("합계 : "+sum);

	}

}

</code>

====do ~while문====
<code java>
package chapter05;

public class DoWhileEx {

	public static void main(String[] args) {
		
		int i = 10;
		
		do {
			System.out.println("i = "+i);
		}while (i < 10);
		
	}

}

</code>

====중첩 반복문====

**구구단 만들기**

<code java>
package chapter05;

public class Gugu {

	public static void main(String[] args) {
		
		for (int j=2; j<10; j++) {
			for (int i=1; i<10; i++) {
				System.out.println("j = "+j+", i = "+i);
			}
		}
		
	}

}

</code>

<code java>
package chapter05;

public class Gugu2 {

	public static void main(String[] args) {
		
		for (int j=2; j<10; j++) {
			System.out.println("["+j+"단]");
			for (int i=1; i<10; i++) {
				System.out.println(j + " * " + i + " = " + j*i);
			}
		}
		
	}

}

</code>

==== 반복문의 중지 (break과 continue)====

<code java>

package chapter05;

public class BreakEx3 {

	public static void main(String[] args) {
		
		target:for (int i=0; i<5; i++) {
			for (int j=0; j<5; j++) {
				if (j==3) {
					break target;
				}
				System.out.println("i="+i+", j="+j);
			}
		}
		
	}

}

</code>

<code java>

package chapter05;

public class ContinueEx {

	public static void main(String[] args) {
		
		for (int i=0; i<10; i++) {
			if (i == 5) {
				continue;
			}
			System.out.println(i);
		}
		
	}

}

</code>