Dark Horse programmer--"Dark Horse video Notes" The use of the C language Foundation while

One. Format:

   1:  while (condition)

   2:  

   3:  {

   4:  

   5:   loop body

   6:  

   7:  }

   8:  

Two. Operating principle

1. If the initial condition is not established, the loop body will never be executed

2. If the condition is set up, a loop body is executed, the execution is completed, and the condition is determined again.

Three. While common two statements: break and Continue

   1:  int count = 0;

   2:  

   3:  while (count<50)

   4:  

   5:  {

   6:  

   7:  ++count;

   8:  

   9:  if (count%10! = 0)

  Ten:  

One   :  {

  :  

  :  printf ("Do%d push-ups \ n", Count);

  :  

  :  }

  :  

  :  }

  :  

1.break, directly ending the entire while loop

   1:  int count=0;

   2:  

   3:  while (Count < 50)

   4:  

   5:  {

   6:  

   7:  ++count;

   8:  

   9:  printf ("Do%d push-ups \ n", Count);

  Ten:  

One   :  If (count = = 20)

  :  

  :  {

  :  

  :  break;

  :  

  :  }

  :  

  :  }

  :  

  :  return 0;

  :  

  :  }

  :  

2.continue, end the current loop body and go to the next loop body execution

   1:  int count=0;

   2:  

   3:  while (count<50)

   4:  

   5:  {

   6:  

   7:  ++count;

   8:  

   9:  if (count%10 = = 0)

  Ten:  

One   :  {

  :  

  :  //end this cycle directly and enter the next cycle

  :  

  :  continue;

  :  

  :  }

  :  

  :  printf ("Do%d push-ups \ n", Count);

  :  

  :  }

  :  

Four. The common dead loop of the while statement

1. The simplest cycle of death

   1:  while (1);

2. Never-ending "hahaha"

   1:  while (10)

   2:  

   3:  {

   4:  

   5:  printf ("haha \ n");

   6:  

   7:  }

   8:  

Five. While application small example

   1:  /*

   2:  

   3:   Prompts the user to enter a positive integer n, computes the 1+2+3+...+n and

   4:  

   5:  * /

   6:  

   7:  #include <stdio.h>

   8:  

   9:  int main ()

  Ten:  

One   :  {

  :  

//1. Prompt for input   

  :  

  :  printf ("Please enter a positive integer: \ n");

  :  

+   :  //2. Receive input

  :  

+   :  //define variable save user input integer

  :  

  :  int n;

  :  

At   :  scanf ("%d", &n);

  :  

  :  if (n<=0)

  £ º  

  :  {

  :  

  :  printf ("illegal input \ n");

  :  

  :  return 0;

  :  

  :  }

  :  

  :  //3. Calculation

  £ º  

  Panax notoginseng  ://(1 + N) * N/2;

  :  

  :  //define variable saving and

Max   :  

In   :  int sum = 0;

  £ º  

Number   :  int//value added by default

  :  

  :  while (number < n)

  :  

  :  {

  :  

  £  number++;

  :  

  Wuyi:  //cumulative

  :  

  :  }

Wu   :  

  :  printf ("%d\n", sum);

  :  

  £ º  return 0;

  :  

  :  }

  :  

Dark Horse programmer--"Dark Horse video Notes" The use of the C language Foundation while