과제 #2 조건문, 반복문

public class Main {
    public static void main(String[] args) {
        System.out.println("for문으로 정방향");
        String a = "";

        for (int i = 0; i < 5; i++) {
            a += "*";
            System.out.println(a);
        }

        System.out.println("----------");
        System.out.println("for문으로 역방향");

        for (int i = 0; i < 5; i++) {
            System.out.println(a);
            a += "\b";
        }

        System.out.println("----------");
        System.out.println("for문으로 정방향 + 역방향");

        String b = "";

        for (int i = 0; i < 2; i++) {
            for (int x = 0; x < 5; x++) {
                if (i == 0) {
                    b += "*";
                    System.out.println(b);
                } else if (i == 1) {
                    b += "\b";
                    System.out.println(b);
                }
            }
        }

        System.out.println("----------");
        System.out.println("for문으로 다이아몬드 만들기");

        String c = "*";
        String d = "     ";

        for (int i = 0; i < 2; i ++) {
            if (i == 1) System.out.println(c);
            for (int x = 0; x < 5; x++) {
                if (i == 0) {
                    System.out.println(d + c);
                    c += "**";
                    d += "\b";
                } else if (i == 1) {
                    c += "\b\b";
                    d += " ";
                    System.out.println(d + c);
                }
            }
        }

        System.out.println("----------");
        System.out.println("switch문");

        int e = 5;

        switch (e) {
            case 1:
                System.out.println("*");
                break;
            case 2:
                System.out.println("*");
                System.out.println("**");
                break;
            case 3:
                System.out.println("*");
                System.out.println("**");
                System.out.println("***");
                break;
            case 4:
                System.out.println("*");
                System.out.println("**");
                System.out.println("***");
                System.out.println("****");
                break;
            case 5:
                System.out.println("*");
                System.out.println("**");
                System.out.println("***");
                System.out.println("****");
                System.out.println("*****");
                break;
        }

        System.out.println("----------");
        System.out.println("while문 안의 if문");

        int i = 1;
        String y = "";

        while (i != 11) {
            if (i < 6) {
                y += "*";
                System.out.println(y);
                i += 1;
            } else if (i < 11) {
                y += "\b";
                i += 1;
                System.out.println(y);
            }
        }

        System.out.println("----------");
        System.out.println("while문 안의 while문");

        int k = 1;
        String h = "";

        while (k != 11) {
            while (k < 6) {
                k += 1;
                h += "*";
                System.out.println(h);
            }
            k += 1;
            h += "\b";
            System.out.println(h);
        }
    }
}