'float' vs. 'double' precision

Question

The code

float x  = 3.141592653589793238;
double z = 3.141592653589793238;
printf(\"x=%f\\n\", x);
printf(\"z=%f\\n\", z);
printf(\"x=%20.18f\\n\", x);
print         


        

Answer 1

It's not exactly double precision because of how IEEE 754 works, and because binary doesn't really translate well to decimal. Take a look at the standard if you're interested.