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

As Kevin Haines points out, ints have the natural size suggested by the execution environment, which has to fit within INT_MIN and INT_MAX.

The C89 standard states that UINT_MAX should be at least 2^16-1, USHRT_MAX 2^16-1 and ULONG_MAX 2^32-1 . That makes a bit-count of at least 16 for short and int, and 32 for long. For char it states explicitly that it should have at least 8 bits (CHAR_BIT). C++ inherits those rules for the limits.h file, so in C++ we have the same fundamental requirements for those values. You should however not derive from that that int is at least 2 byte. Theoretically, char, int and long could all be 1 byte, in which case CHAR_BIT must be at least 32. Just remember that "byte" is always the size of a char, so if char is bigger, a byte is not only 8 bits any more.