Question

As the title says,does the visual studio distinguish these two files by their suffix?.c or .cpp?
I also have another question.At first,I stated the program like this:

int main(int argc, char **argv)
{
  LARGE_INTEGER TimeStart;
  LARGE_INTEGER TimeEnd;
  QueryPerformanceCounter(&TimeStart);
  static double Freq;
  static int getfreq; 
  double mu,om;
  double *v;
  int it,i,j;
 ....
}

but it brings out many problems:

1>sor2d.c(23): error C2143: syntax error : missing ';' before 'type'
1>sor2d.c(24): error C2143: syntax error : missing ';' before 'type'
1>sor2d.c(25): error C2143: syntax error : missing ';' before 'type'
1>sor2d.c(26): error C2143: syntax error : missing ';' before 'type'

23 ling points to “static double Freq;”
but if I put “QueryPerformanceCounter(&TimeStart);” after the data allocation,the compiler can succeed.Could someone tell me why this happened,was is just because of my carelessness of omitting something or ignorance…?

Answer 1

In C, all variables must be declared before calling any methods.

Visual Studio will, by default, compile .C files as C. You can override this.