C# 學習 16 循環與跳轉

迭代（循環）語句 && 跳轉語句

1. while
   

2. do while
   和While類似

   continue與break的區別，看下面的例子

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            int score = 0;
            bool canContinue = true;
            do
            {
                int x;
                Console.WriteLine("Please input first number");
                string str1 = Console.ReadLine();
                if (str1.ToLower() == "end")
                {
                    break;
                }
                try
                {
                     x = int.Parse(str1);

                }
                catch
                {
                    Console.WriteLine("Re Input");
                    continue;
               
                }

                Console.WriteLine("Please input second number");
                string str2 = Console.ReadLine();
                if (str2.ToLower() == "end")
                {
                    break;
                }
                int y;
                try
                {
                    y = int.Parse(str2);
                }
                catch 
                {

                    Console.WriteLine("Re Input ");
                    continue;
                }
                

                int sum = x + y;
                if (sum==100)
                {
                    score++;
                    Console.WriteLine("Correct{0}+{1}={2}",x,y,sum);
                }
                else
                 {
                    Console.WriteLine("Error{0}+{1}={2}",x,y,sum);
                    canContinue = false;
                }

            }while (canContinue) ;
            Console.WriteLine("Your Score is {0}",score);
            Console.WriteLine("Game Over");
        }
    }
}

3. for
   
4. foreach
   集合遍歷循環，枚舉一個集合中的元素

什麼樣的集合可以被枚舉，帶有IEnumerable的類

什麼是迭代器。
指月，

return

原則：儘早return