/in/ex5.cpp: In member function 'void bookInventory::removeBook(int)':
/in/ex5.cpp:43:21: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     if(ID < 1 || ID > numBooks){
                  ~~~^~~~~~~~~~
/in/ex5.cpp:47:31: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
         for(int i = ID - 1; i < numBooks; i++){
                             ~~^~~~~~~~~~
/in/ex5.cpp: In member function 'void bookInventory::printInventory() const':
/in/ex5.cpp:61:22: error: comparison between signed and unsigned integer expressions [-Werror=sign-compare]
     for(int i = 0; i < numBooks; i++){
                    ~~^~~~~~~~~~
cc1plus: all warnings being treated as errors
/in/compile/Makefile:26: recipe for target 'ex5.o' failed
make: *** [ex5.o] Error 1