return 0

return 0

In the context of computer programming, specifically within languages like C, C++, and Java, "return 0" is a statement commonly used at the end of the main function. It indicates that the program has executed successfully and has terminated without encountering any errors.

The return statement, in general, causes a function to stop execution and pass control back to the calling function (or the operating system if the function is main). The value following the return keyword is passed back as the function's return value.

For the main function, a return value of 0 traditionally signifies successful completion to the operating system. Non-zero return values usually indicate that an error or exception occurred during the program's execution. These error codes can be used by other programs or scripts to determine if the program ran as expected.

While relying on the implicit return 0; at the end of main has become permissible in certain C++ standards (since C++11), explicitly including return 0; is considered good programming practice, as it clearly communicates the intended outcome and enhances code readability. The meaning of a non-zero return value is operating system and compiler specific; conventions for the meanings of specific codes do exist but are not universally adopted.