Evaluating the constructor equivalent of a variable - c++

Question

I have the constructor
class MyFrame : public wxFrame { // defines the options on the top bar of the screen here we have:
public:
MyFrame();
private:
void OnHello(wxCommandEvent& event); // hello option
void OnExit(wxCommandEvent& event); // exit option
void OnAbout(wxCommandEvent& event); // about option
void OnHelp(wxCommandEvent& event); // event option
// void OnCourseTextBoxClicked(wxCommandEvent &event);
void OnOneHundredLevelDisplayGpButtonClicked(wxCommandEvent &event);
void OnTwoHundredLevelDisplayGpButtonClicked(wxCommandEvent &event);
void OnThreeHundredLevelDisplayGpButtonClicked(wxCommandEvent &event);
void OnFourHundredLevelDisplayGpButtonClicked(wxCommandEvent &event);
void OnFiveHundredLevelDisplayGpButtonClicked(wxCommandEvent &event);
void OnDisplayCgpaButtonClicked(wxCommandEvent &event);
// Common Courses equating their credit load
/* 100 LEVEL FIRST SEMESTER */
int CHM111 = 3;
int CHM113 = 3;
int MTH111 = 3;
int MTH112 = 3;
int PHY111 = 3;
int PHY113 = 3;
int GST111 = 2;
int GST112 = 2;
/* 100 LEVEL SECOND SEMESTER */
int CHM122 = 3;
int CHM124 = 3;
int MTH123 = 3;
int MTH125 = 3;
int PHY109 = 2;
int PHY124 = 4;
int GST121 = 2;
int GST122 = 2;
int GST123 = 2;
int LEVEL_TOTAL_100 = 47;
}
And somewhere else in the code base, some text is entered into a text box. The text box is supposed to contain one of the variables defined in the constructor which evaluate to their respective integers.
When the text box's content is evaluated e.g.:
course_one_text_box->GetValue();
evaluates
CHM111
I want to grab the constructor integer value for the CHM111 which is 3. I want to employ this value in a mathematical formula.
How do I do this?
Is there a particular syntax that grabs the constructor recorded version of the variable instead?
Thanks.

Answer 1

wxTextCtrl works with wxString, not with numbers.
But it's really easy to get a number from a wxString: Use wxString::ToCLong. For example:
long value;
mystring = mytextctrl->GetValue();
if ( ! mystring.ToCLong(&value) )
some message here, conversion failed (not a number)
//Your comparisons:
if ( value == (long)CHM111 )
....
So, if the user enters 3 the 'if' is true because CMH111 is initialized as 3
Notice the (long) cast from an int to avoid compiler warning. Why not use long instead of int for the type of CHMxxx?
What is not possible in C++ is to compare against the name of a variable.

Answer 2

#Alvindera97,
Is your program should restrict the user to enter only those constants? Then you have a wrong tool for the job!
Look at the wxComboBox/wxChoice. This way the user will have the only choice to select from the list and you won't need to keep those constants definitions in the class.
Hope this helps!