2016.10.20 韬光养晦

今天复习java的流程结构,还是那句话,基础还是很重要.

1.switch

public class TestSwitch {
    public static void main(String[] args) {
         int a = 1;
         // String b = "今天是";
         switch (a) {
         case 1:
         System.out.println("星期一");
         break;
         case 2:
         System.out.println("星期二");
         break;
         case 3:
         System.out.println("星期三");
         break;
         case 4:
         System.out.println("星期四");
         break;
         case 5:
         System.out.println("星期五");
         break;
         case 6:
         System.out.println("星期六");
         break;
         case 7:
         System.out.println("星期天");
         break;
         default:
         System.out.println("there is nothing");
         }        
    }
}

2.do-wihile

do {
    System.out.println("至少让我执行一次");
   } while (i > 10);

3.for

阶乘

public class TestFor {
    public static void main(String[] args) {
        // 阶乘求值
        int jiecheng = 1;
        int num = 0;
        for (int i = 1; i < 10; i++) {
            jiecheng *= i;
            num += jiecheng;
            System.out.println(jiecheng);
        }
        System.out.println(num);
    }
}

蜜汁706

int bf, mf, lf;
        for (bf = 0; bf < 20; bf++) {
            for (mf = 0; mf < 100; mf++) {
                for (lf = 0; lf < 100; lf++) {
                    if ((bf + mf + lf == 100) && (bf * 5 + mf + lf * 0.5 == 100)) {
                        System.out.println(bf + " " + mf + " " + lf);
                    }
                }
            }
        }

补充一下,可以用for(;;)来进行无限循环,因为这个根本不用判断,不像while True每次都要判断,也算一点点性能优化吧

break&continue&return

public class TestBreakContinueReturn {
    public static void main(String[] args) {
        for (int i = 1; i < 4; i++) {
            System.out.println("这是第" + i + "次外循环");
            for (int j = 1; j < 4; j++) {
                System.out.println("\t" + "这是第" + j + "次内循环");
                break;
            }
        }

        for (int a = 1; a < 10; a++) {
            if (a == 6) {
                continue;
            }
            System.out.println(a);
        }

        for (int a = 1; a < 10; a++) {
            if (a == 8) {
                return;
            }
            System.out.println(a);
        }
        System.out.println("helloworld");
    }
}

break是跳出当前循环;continue是跳过当前操作继续循环;return是调处整个main方法

今天学到了activity的查看方法,很开心,很有成就感,不过今晚得把appium给入门了,干!!!