Java 语句

/* IF 语句*/
public class TestIF {
    public static void main(String[] args) {
        int i = 20;
        if(i < 20) {
            System.out.println("<20");
            System.out.println("<20");
        } else if (i < 40) {
            System.out.println("<40");
        } else if (i < 60) {
            System.out.println("<60");
        } else {
            System.out.println(">=60");
        }

        System.out.println(">=60");

    }
}

/* while 语句 */
public class TestWhile {
    public static void main(String[] args) {
        int i = 0;
        while(i < 10) {
            System.out.println(i);
            i++;
        }

        i = 0;
        do {
            i++;
            System.out.println(i);
        } while(i < 10);
    }
}

/* switch 语句 */
public class TestSwitch {
    public static void main(String[] args) {
        int i = 8;
        switch(i) {
            case 8 :
            case 3 :
            case 2 :
                System.out.println("C");
                break;
            case 9 :
                System.out.println("D");
                break;
            default:
                System.out.println("error");
        }
    }
}

课件： Java 语句.pdf