Duplicate Symbol Error from C functions in Objective-C
You should put declarations in the .h file, make them extern, and move definitions into a .c or .m file.
From this
myfunctions.h
int max(int a, int b) { return a>b ? a : b;}Move to this:
myfunctions.h
extern int max(int a, int b); // declarationmyfunctions.c
int max(int a, int b) { return a>b ? a : b;}