在您的代码中，则变量"i"没有初始化.
也许您可以更改"for(i = 0; i< n; i ++)".>

In your code,the variables "i" isn''t initialize.
maybe you can change "for(i=0;i<n;i++)".>

您的问题不清楚，您的英语也不清楚(抱歉表示... )

Your question is not clear and so is your English (sorry for indicating that...)

如果输出应为20星(*)，则可以通过以下方式进行操作:

If the output should be 20 stars (*), you can do it in the this way:

#include <stdio.h>
#include <string.h>
#include <conio.h>

int main ()
{
  char str[21]; //21 because 20 stars and '\0' at the end 
  strcpy (str,"*********************"); //fill 
  //or char str[21] = {"*********************"};
  //or char str[] = {"*********************"};  //automatically preserve the size
  printf(str);
  getch();
  return 0;
}

C-我差点忘了它;)

C - i almost forgot it ;)