In C, the return 0; statement in the main() function is not strictly necessary in C99 and later standards. If control reaches the end of the main() function without a return statement, the compiler automatically assumes return 0;. However, it is considered good practice to explicitly include return 0; for clarity and to indicate that the program has completed successfully.
In earlier versions of C (before C99), it was required to include a return statement in main(). Therefore, while it's not always necessary in modern C, including it is a good habit.
