Question

A compiler checks the syntax of source code from the text file. Why is it necessary to save it with an extension .c or .cpp?

I tried this on gcc but it does not compile a file with an extension other than .c and .cpp!!

Answer 1

The compiler won’t guess the language of the code in a file by looking at the text – you have to tell it what to compile as. Nearly every compiler allows this to be passed as a flag or it will infer it from the file extension. You’re quite free to compile a .cpp file as pure C by passing the appropriate flag to your compiler so it needn’t infer it. However, this is a situation where following convention helps both you (less flags to pass around) and other programmers (who know the language from a quick ls).