Hi Prajwal see this header file stdio.h at C:\Program Files (x86)\CodeBlocks\MinGW\include and after removing the preprocessors,you will find scanf() function with its statement like below :
int scanf(const char *fmt, ...) {
int rc;
va_list args;
va_start(args, fmt);
rc = _input(stdin, fmt, args);
return rc;
}
here it also includes stdarg.h and stddef.h where these functions used inside scanf() are defined.