C: “invalid use of undefined type ‘struct X’ & dereferencing pointer to incomplete type” errors

Question

I\'ve been perusing similar questions to mine for a couple of days but still haven\'t found a solution. Thanks any any help:

I have two files, one containing methods

Answer 1

While in there, you may also want to change your definitions.

Better way so you understand what's going on:

struct fraction {
   int integer;
   int num;
   int den;
};
typedef struct fraction fractionType; // We can now use fractionType and it'll be struct fraction

typedef fractionType * fractionTypePtr; // We can now use fractionTypePtr and it will be a pointer to a fractionType which is a struct fraction