From java to C++

[Lektroluv]

I've have made a project in java.
With some adjustments, it should be possible to make this program work in c++.
I've implemented most of the things.
But now I'm a little bit stuck.
This is my log:

Compiler: Default compiler
Building Makefile: "C:...\Makefile.win"
Bezig met uitvoeren van make...
make.exe -f "C:...\Makefile.win" all
g++.exe -c main.cpp -o main.o -I"C:/Dev-Cpp/lib/gcc/mingw32/3.4.2/include" -I"C:/Dev-Cpp/include/c++/3.4.2/backward" -I"C:/Dev-Cpp/include/c++/3.4.2/mingw32" -I"C:/Dev-Cpp/include/c++/3.4.2" -I"C:/Dev-Cpp/include"

In file included from Jury.h:1,
from main.cpp:5:
Kandidate.h:7: error: redefinition of class Kandidate' Kandidate.h:7: error: previous definition ofclass Kandidate'

main.cpp: In function `int main(int, char**)':

main.cpp:12: error: invalid conversion from const char*' tochar'
main.cpp:12: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:13: error: invalid conversion fromconst char' to char' main.cpp:13: error: initializing argument 1 ofKandidate::Kandidate(char, int)'
main.cpp:14: error: invalid conversion from const char*' tochar'
main.cpp:14: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:15: error: invalid conversion fromconst char' to `char'

main.cpp:15: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:16: error: invalid conversion fromconst char' to char' main.cpp:16: error: initializing argument 1 ofKandidate::Kandidate(char, int)'
main.cpp:17: error: invalid conversion from const char*' tochar'
main.cpp:17: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:18: error: invalid conversion fromconst char' to char' main.cpp:18: error: initializing argument 1 ofKandidate::Kandidate(char, int)'
main.cpp:19: error: invalid conversion from const char*' tochar'
main.cpp:19: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:20: error: invalid conversion fromconst char' to char' main.cpp:20: error: initializing argument 1 ofKandidate::Kandidate(char, int)'
main.cpp:21: error: invalid conversion from const char*' tochar'
main.cpp:21: error: initializing argument 1 of Kandidate::Kandidate(char, int)' main.cpp:22: error: invalid conversion fromconst char' to char' main.cpp:22: error: initializing argument 1 ofKandidate::Kandidate(char, int)'
main.cpp:23: error: invalid conversion from const char*' tochar'
main.cpp:23: error: initializing argument 1 of `Kandidate::Kandidate(char, int)'

make.exe: *** [main.o] Error 1

Excecution complete

This is a part of main.cpp:

int main(int argc, char *argv[]) {
Kandidate miss1("Emma", 9901);
Kandidate miss2("Veerle", 9902);
Kandidate miss3("Laura", 9903);
Kandidate miss4("Sandra", 9904);
......

This is a part of Kandidate.cpp:

include "Kandidate.h"

include <iostream>

using namespace std;

Kandidate::Kandidate(char naam, int nummer) {
    this->naam = naam;
    this->nummer = nummer;
    cout << "Miss " << naam << "\tmet nummer\t" << nummer << endl;
}

[cpns]

Additionally, with C style strings, you probably cannot do this:

this->naam = naam;

That at best would merely copy a pointer. It may work in this limited case because you originally used a literal constant, whose address may persist, but it does not copy the string, so if the original string were a temporary variable, you'd be in trouble.

To copy C strings you need to use the strcpy() function. However for that to work, this->naam must have space allocated to it, so must either be an array or a pointer to some otherwise allocated space - not an uninitialised pointer.

As I suggested, this is all much easier if you were to use std::string.

Clifford

[cpns]

The errors are reported for line 7 of Kandidate.h and 12-23 of main.cpp. The least you could do is post all teh code referenced in the error messages.

With respect to Kandidate.h(7), the most likely guess is lack of include guards ( http://en.wikipedia.org/wiki/Include_guard )

With respect to main.cpp(12) and all the others, did you actually read the error message? Is is exactly what it says, you have passed a const char* argument to a function that expects a char argument.

If the char argument concerned was intended to be a C string, then it should be char*. A char is simply a small integer, you need an array of char to hols a C string. Now that said, this is C++ and you no longer need ot use C's char array kludge to perform string handling, C++ has a std::string class, that as a Java programmer you will almost certainly be more comfortable with.

A hint when reading GCC error messages, the compiler often uses more than one line for what is effectively a single message; so for example:

> main.cpp:12: error: invalid conversion from const char*' tochar'
> main.cpp:12: error: initializing argument 1 of `Kandidate::Kandidate(char, int)'

is just one error message, and needs to be read together. Like "invalid conversion from const char*' tochar' when initializing argument 1 of `Kandidate::Kandidate(char, int)' ".

You should find that the messages make far more sense when you read them like that. Often teh two lines reference separate code lines - usually the usage location and the associated definition or declaration location.

Clifford.

[cpns]

> The least you could do is post all the code
> referenced in the error messages.

I meant in such a way that we may match the lines with the errors. Upon reflection I am assuming that

Kandidate miss1("Emma", 9901);

is line 12? But you still did not post any part of kandidate.h