static void Main(string[] args)
        {
            //switch語句
            int a = 10;
            switch (a)
            {
                case 5:
                    Console.WriteLine("Five");
                    break;  //每個case子句結束時必須使用跳轉指令
                case 6:
                    Console.WriteLine("Six");
                    break;
                case 7:
                    Console.WriteLine("Seven");
                    break;
                case -1:
                    goto case 5;    //goto case x 也是一個跳轉指令，還有goto default、return、throw、continue、或者goto label
                default:    //default子句不論出現(xiàn)在什么地方都會在最后才執(zhí)行
                    Console.WriteLine("Num");
                    break;
            }



            //迭代語句
            //while
            int b=0;
            while (b < 5)
            {
                Console.WriteLine(b);   //0,1,2,3,4
                b++;
            }

            //do-while
            int c = 0;
            do
            {
                Console.WriteLine(c);
                c++;
            }
            while(c < 5);

            //for
            for(int i=0; i<5; i++)
            {
                Console.WriteLine(i);
            }
            //打印前10個斐波那契數(shù)
            for(int i = 0, prevFib = 1, curFib = 1; i < 10; i++)
            {
                Console.WriteLine(prevFib); //1,1,2,3,5,8,13,21,34,55
                int newFib = prevFib + curFib;
                prevFib = curFib;
                curFib = newFib;
            }

            //foreach
            foreach (char d in "apple")
                Console.WriteLine(d);



            //跳轉語句
            //break--用于結束迭代或switch語句的執(zhí)行
            int e = 0;
            while (true)
            {
                if (e++ < 5)
                    break;
            }

            //continue--放棄循環(huán)體中其后的語句，繼續(xù)下一輪迭代
            for(int i = 0; i < 10; i++)
            {
                if ((i % 2) == 0)
                    continue;
                Console.WriteLine(i);   //1,3,5,7,9
            }

            //goto--將執(zhí)行點轉移到語句塊中的指定標簽處
            int f = 0;
            startLoop: if (f <= 3)
            {
                Console.WriteLine(f);   //0,1,2,3
                f++;
                goto startLoop;
            }

            //return--用于退出方法。

            //throw--拋出異常來表示有錯誤發(fā)生

        }