[JAVA] 4. 반복문 Ⅱ. 구구단 하드코딩

1. 구구단

1. 하드코딩

        System.out.println("2*1=2");
        System.out.println("2*2=4");
        System.out.println("2*3=6");
        System.out.println("2*4=8");
        System.out.println("2*5=10");
        System.out.println("2*6=12");
        System.out.println("2*7=14");
        System.out.println("2*8=16");
        System.out.println("2*9=18");
        System.out.println();

        System.out.println("3*1=3");
        System.out.println("3*2=6");
        System.out.println("3*3=9");
        System.out.println("3*4=12");
        System.out.println("3*5=15");
        System.out.println("3*6=18");
        System.out.println("3*7=21");
        System.out.println("3*8=24");
        System.out.println("3*9=27");
        System.out.println();

        System.out.println("4*1=4");
        System.out.println("4*2=8");
        System.out.println("4*3=12");
        System.out.println("4*4=16");
        System.out.println("4*5=20");
        System.out.println("4*6=24");
        System.out.println("4*7=28");
        System.out.println("4*8=32");
        System.out.println("4*9=36");
        System.out.println();

2. 모듈화

        // 2단
        int a = 2;
        System.out.println(a + "*1=" + a * 1);
        System.out.println(a + "*2=" + a * 2);
        System.out.println(a + "*3=" + a * 3);
        System.out.println(a + "*4=" + a * 4);
        System.out.println(a + "*5=" + a * 5);
        System.out.println(a + "*6=" + a * 6);
        System.out.println(a + "*7=" + a * 7);
        System.out.println(a + "*8=" + a * 8);
        System.out.println(a + "*9=" + a * 9);
				
				// 3단
        a++;
        System.out.println(a + "*1=" + a * 1);
        System.out.println(a + "*2=" + a * 2);
        System.out.println(a + "*3=" + a * 3);
        System.out.println(a + "*4=" + a * 4);
        System.out.println(a + "*5=" + a * 5);
        System.out.println(a + "*6=" + a * 6);
        System.out.println(a + "*7=" + a * 7);
        System.out.println(a + "*8=" + a * 8);
        System.out.println(a + "*9=" + a * 9);
				
				// 4단
        a++;
        System.out.println(a + "*1=" + a * 1);
        System.out.println(a + "*2=" + a * 2);
        System.out.println(a + "*3=" + a * 3);
        System.out.println(a + "*4=" + a * 4);
        System.out.println(a + "*5=" + a * 5);
        System.out.println(a + "*6=" + a * 6);
        System.out.println(a + "*7=" + a * 7);
        System.out.println(a + "*8=" + a * 8);
        System.out.println(a + "*9=" + a * 9);

3. 반복문 사용

        int a = 2;
        for (int i = 0; i < 8; i++) {
            System.out.println(a + "*1=" + a * 1);
            System.out.println(a + "*2=" + a * 2);
            System.out.println(a + "*3=" + a * 3);
            System.out.println(a + "*4=" + a * 4);
            System.out.println(a + "*5=" + a * 5);
            System.out.println(a + "*6=" + a * 6);
            System.out.println(a + "*7=" + a * 7);
            System.out.println(a + "*8=" + a * 8);
            System.out.println(a + "*9=" + a * 9);
            a++;
        }

4. 2중 반복문 사용

        for (int i = 2; i <= 9; i++) {
            for (int b = 1; b <= 9; b++) {
                System.out.println(i + "*" + b + "=" + (i * b));
            }
            System.out.println();
        }