C 函數(shù)參數(shù)

    #include <stdio.h> 
    #include <stdarg.h> 
      //from www. j  av a  2 s  .c  om
    double average(double v1 , double v2,...);       // Function prototype 
      
    int main(void) 
    { 
      double v1 = 1.5, v2 = 2.5; 
      int num1 = 6, num2 = 5; 
      long num3 = 2L, num4 = 12L; 
      
      printf("Average = %.2lf\n", average(v1, 3.5, v2, 4.5, 0.0)); 
      printf("Average = %.2lf\n", average(1.0, 2.0, 0.0)); 
      printf("Average = %.2lf\n", average( (double)num2, v2,(double)num1, (double)num4,(double)num3, 0.0)); 
      return 0; 
    } 
      
    // Function to calculate the average of two or more arguments 
    double average( double v1, double v2,...) { 
      va_list parg;                      // Pointer for variable argument list 
      double sum = v1 + v2;              // Accumulate sum of the arguments 
      double value = 0.0;                // Argument value 
      int count = 2;                     // Count of number of arguments 
      
      va_start(parg,v2);                 // Initialize argument pointer 
      while((value = va_arg(parg, double)) != 0.0) { 
        sum += value; 
        ++count; 
      } 
      va_end(parg);                                  // End variable argument process 
      return sum/count; 
    } 

#include <stdio.h> 
int main(int argc, char *argv[]) 
{ 
  printf("Program name: %s\n", argv[0]); 
  for(int i = 1 ; i<argc ; ++i) 
    printf("Argument %d: %s\n", i, argv[i]); 
  return 0; 
}