C # syntax ---- program structure (4)

Here we learn a cyclic structure

while loop

grammar:

while (loop condition)

{

   Loop body;

}

Execution: while the program is running, the first determined cycle conditions while brought in parentheses is satisfied, returns true is satisfied, the loop body is executed, executing the

          After once again determine the loop condition, was established to continue the loop, if not established, a quick jump out.

Let's look a little practice:

 

. 1  the using the System;
 2  the using the System.Collections.Generic;
 . 3  the using the System.Linq;
 . 4  the using the System.Text;
 . 5  the using System.Threading.Tasks;
 . 6  
. 7  namespace Panel
 . 8  {
 . 9      class Program
 10      {
 . 11          static  void the Main ( String [ ] args)
 12 is          {
 13 is              // find all integers and 1-100
 14              @ loop: accumulation process
 15              @ cycling conditions: I <= 100 
16              int i = 1;
17             int sum = 0;
18             while (i<=100)
19             {
20                 sum += i;
21                 i++;
22             }
23             Console.WriteLine(sum);
24             Console.ReadKey();
25         }
26     }
27 }

 

Here to talk about a very important break keyword

(1) switch-case structure can bounce

(2) out of the current cycle.

Consider the following example of a

 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace Panel
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             int i = 1;
14             int j = 1;
15             while(I <= 10 )
 16              {
 . 17                  while (J <= 10 )
 18 is                  {
 . 19                      Console.WriteLine ( " I was inside the while loop " );
 20 is                      J ++ ;
 21 is                      BREAK ;
 22 is                  }
 23 is                  Console.WriteLine ( " I am out the while loop " );
 24                  I ++ ;
 25              }
 26 is              the Console.ReadKey ();
 27          }
28     }
29 }

 

This example illustrates the effect of a good break of

 

 

 break generally not used alone, but used in conjunction with determining if expressed, when certain conditions are met, the not recycled.

Everyone to practice several codes

Exercise 1

 

 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace Panel
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             string userNmae = string.Empty;
14             string userPwd = string.Empty;
15              the while (! UserNmae = " ADMIN " ! || UserPwd = " 888888 " )
 16              {
 . 17                  Console.WriteLine ( " Please enter the user name " );
 18 is                  userNmae = Console.ReadLine ();
 . 19                  Console.WriteLine ( " Enter password " );
 20 is                  UserPwd = Console.ReadLine ();
 21 is              }
 22 is              Console.WriteLine ( " login success " );
 23             Console.ReadKey();
24         }
25     }
26 }

 

Exercise 2: Enter the number of classes, followed by input student achievement, grade point average and class calculate the total score.

 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 
 7 namespace Panel
 8 {
 9     class Program
10     {
11         static void Main(string[] args)
12         {
13             Console.WriteLine("请输入班级人数");
14             int count =Convert.ToInt32 (Console.ReadLine ());
 15              int I = . 1 ;
 16              int SUM = 0 ;
 . 17  
18 is              the while (I <= COUNT)
 . 19              {
 20 is                  Console.WriteLine ( " Please enter {0} examinations INSTITUTE " , I);
 21 is                  int score = Convert.ToInt32 (Console.ReadLine ());
 22 is                  SUM + = score;
 23 is              }
 24              Console.WriteLine ( " {0} class personal total score is the average score of {1} {2 } " , COUNT, SUM, SUM /count);
25             Console.ReadKey();
26         }
27     }
28 }