Hello, while I was pursuing the Ultimate C++ Part 3: Advanced from Mr Mosh Hamedani, in the 6th lesson of the classes section named " getters and setters" he raised a small quiz which I still am unable to solve, and in spite of copying the exact code and repeated the entire section to figure out where the bug is but still the same error so please help advise me and thanks in advance.
Attached is the code for the header file, I had 3 files the header and CPP implementation file for the class in addition to the main file where I wanted to use the class. The error I get is (: undefined reference to `TextBox::getvalueabi:cxx11’
collect2.exe: error: ld returned 1 exit status
make: *** [: main] Error 1) despite me including the header file on the top of all the three files