Question

How can I fscanf for both float and double, as I declared a global precision once in single precision (float) and once in double precision (double)… so when I run it, I have to change it everytime that I convert to a different type

in double (%lf)
in single (%f)

fscanf(fp1,"%lf", &a[i][j]);

so is there’s a way that works for both and no need to change it every time?

Answer 1

Been a while since I did any coding in C, so you may want to confirm via experimentation, but all single-precision floats are valid double-precision floats, so you could just use ‘%lf’ in the fscanf, store to a temporary double-precision float, and then use logic to assign it to the correct variable.

Alternatively, if you’re using “#define”s, you could just do something like:

#define USE_DOUBLE
#ifdef USE_DOUBLE
#define STORTYPE double
#define SCANSTRING "%lf"
#else
#define STORTYPE float
#define SCANSTRING "%f"
#endif
...
STORTYPE a[x][y];
fscanf(fp1,SCANSTRING, &a[i][j]);