return 0 vs return 1 in C++

The Return statement in C/C++:

• C and C++ support return statements, which are also called jump statements.
• It is used to return a value from the function or stop the execution of the function. For more information on return statements, please refer to article return statement in C/C++ with examples.

There are two scenarios in which return statements will be used:                  

:

• In this case, the return statement stops the execution of the program, and 0 or 1 will denote the execution status.
• These status codes will be just used as a convention for a long time in C language because the language does not support the objects and classes, and exceptions.
• return 0: A return 0 means that the program will execute successfully and did what it was intended to do.
• return 1: A return 1 means that there is some error while executing the program, and it is not performing what it was intended to do.

Important characteristics of the return statement: 

• If exit with a status other than 0 then, print an error message to stderr.
• There are different conventions depending on the operating system about return codes.
• The Operating System may itself terminate the program with specific exit status codes if some invalid operations are performed.

Below is a program to illustrate the use of return 0 and return 1 inside the main function:

Division by zero is not possible.

Time Complexity: O(1)
Auxiliary Space: O(1)

:

• C++ treats boolean as a completely separate data type that has only 2 distinct values, i.e., true and false.
• The values 1 and 0 are of type int and are not implicitly convertible to boolean, that means:
  • returning false from a function.
  • returning true from a function.

Below is a program to illustrate the use of return 0 and return 1 inside the user-defined function:

You are an adult

Time Complexity: O(1)
Auxiliary Space: O(1)

Conclusion: