space for variables
yahaa, are you asking about C, or some other language?
Yes, C integer sizes depend on the compiler, although the ANSI C standard specifies minimum number of integer bits, and floating point resolution (but not number of floating point bits). Refer to your header files limits.h, float.h, stdint.h.
char is at least 8 bits.
short int is at least 16 bits.
int is at least 16 bits.
long int is at least 32 bits.
long long int is at least 64 bits.
charbits <= shortintbits <= intbits <= longintbits <= longlongintbits.
The compiler authors usually choose integer and floating-point sizes that suit the CPU architecture and comply with the ANSI C standard. Turbo C dates back to the days of 16-bit CPUs such as 8086 and 80286, so it uses 16-bit int. Most hardware floating point units comply with IEEE Std 754, so we see a lot of 32-bit floats and 64-bit doubles.