g++ compiling

[nomad5000]

I can't compile this using g++
michael@michael:~/g++$ g++ program.cpp
//ClassA.h
class ClassA{
private:
int atribute;
public:
ClassA(int atribute);
};
//ClassA.cpp
#include "ClassA.h"

ClassA::ClassA(int atribute){
this->atribute = atribute;
}
//program.cpp
#include "ClassA.h"
#include <iostream>

int main(){
ClassA object(10);
return 1;
}

the compiler returns the folowing error msg:

/tmp/ccwwAJmP.o(.text+0x1f): In function `main':
: undefined reference to `ClassA::ClassA[in-charge](int)'
collect2: ld returned 1 exit status

[tyreld]

You need to provide the compiler with all the necessary source files. You neglected to tell it that ClassA.cpp contains code needed to properly link the program. The following should solve your problem.

g++ program.cpp ClassA.cpp

[nomad5000]

thank you very much!