What is the difference between an int and a long in C++?

Question

Correct me if I am wrong,

int is 4 bytes, with a range of values from -2,147,483,648 to 2,147,483,647 (2^31)
long is 4 bytes, with a range of values from -2,147,

Answer 1

For the most part, the number of bytes and range of values is determined by the CPU's architecture not by C++. However, C++ sets minimum requirements, which litb explained properly and Martin York only made a few mistakes with.

The reason why you can't use int and long interchangeably is because they aren't always the same length. C was invented on a PDP-11 where a byte had 8 bits, int was two bytes and could be handled directly by hardware instructions. Since C programmers often needed four-byte arithmetic, long was invented and it was four bytes, handled by library functions. Other machines had different specifications. The C standard imposed some minimum requirements.