C++: Basic Concepts: Hello, World!: Return

Return
The last instruction in the program is the return statement. The line return 0; terminates the mainfunction and causes it to return the value 0 to the calling process. A non-zero value (usually of 1) signals abnormal termination. Try It Yourself
 * #include
 * using namespace std;
 * int main
 * cout << "Hello World!";
 * return 0;
 * }
 * return 0;
 * }

Note: If the return statement is left off, the C++ compiler implicitly inserts "return 0;" to the end of the main function.