difference between return 0 and retuen -1

[prathap rudra]

difference between return 0 and return -1 .and exit(0) and exit(1)

[weaknessforcats]

Return values are just made up. many programmers return 0 to indicate the function completed successfully. This leaves all the other integer values to mean what kind of failure occurred.

Functions doing compares between two arguments A and B might return:

0 means A == B
1 means A > B
-1 means A < B

Functions returning pointers usually return 0 if the function fails since a 0 pointer is always invalid. A non-zero return is assumed to be a valid address.

In the case of main() and exit() the 0 means a successful end of the program and -1 means the program terminated in error. There is no access to this value outside the program so it's just there for the programmer to see in the code.