Convert double to its string representation

[minex]

Hi!

I would like to know what's the way to convert a double to its char[8] representation, and vice versa (Char[8] to double)

i.e EXAMPLES -> 1.3e-15 (made up that number)

In VS debugger you can cast double variables with ",s" to get their representation as string which is useful..

Note: I am not after "1.32" -> 1.32

Many Thanks,

 

[xwb]

Something like this?

union 
{
   double dd;
   char cc[8];
} equiv;

double x = 1.3e-15;
equiv.dd = x;
for (int ii = 0; ii < 8; ++ii)
   printf ("%02x ", equiv.cc[ii]);

 

[ArkM]

It's interesting that a trick with union is not legal in C++ because after any assignment to a member of union all other members are undefined (see the C++ Standard.

So OP refers to implementation-defined issues. Well, old good C (brutal force methods work, for example:

double x = 3.14;
char* pchar = reinterpret_cast<char*>(&x);
// that's a double as a char array via pchar pointer

memcopy(&x,"EXAMPLES",sizeof x);
cout << x << '\n';

Keep it simpler...