Hello everyone
I wonder if it is required to write #include <typedef.h> at the begining of the code to use the sizeof operator according to the standard.
The return type of the sizeof operator is size_t and it is defined in typedef library. Therefore I conclude it is required. However I couldn't be sure as the sizeof keyword is mentioned as operator rather than a function in books.
I could experiment it but the results would not be reliable as my compiler accepts printf and scanf even without stdio library.