C++ Undefined Symbol Error - c++

Question

I am Getting undefined symbol error for all the integer and char values.Please Help me.
The int x y and z are not working and also the char value of function.
#include <iostream.h>
#include <conio.h>
#include <math.h>
#include <string.h>
class Calculator
{
public:
int x;
int y;
int z;
char function;
void Calculate()
{
if(function=='+')
{z=x+y;}
else if(function=='-')
{z=x-y;}
else if(function=='*')
{z=x*y;}
else if(function=='/')
{z=x/y;}
else
{cout<<"Wrong Function!!!";}
}
};
void main()
{
clrscr();
Calculator working;
cout<<"Welcome!"<<endl;
cout<<"Enter your first number:"<<endl;
cin>>x;
cout<<"Enter your function:"<<endl;
cin>>function;
cout<<"Enter your second number:"<<endl;
cin>>y;
working.Calculate();
cout<<"Your Result is:"<<z<<endl;
getch();
}

Answer 1

Either use, std::cin, std::cout, std::endl or include std namespace,
using namespace std;

Answer 2

This code compiles:
#include <iostream>
#include <math.h>
#include <string.h>
using namespace std;
class Calculator
{
public:
int x,y;
float z;
void add()
{
cin>>x;
cin>>y;
z=x+y;
cout<<"The addition is:"<<z<<endl;
}
void substract()
{
cin>>x;
cin>>y;
z=x-y;
cout<<"The substraction is:"<<z<<endl;
}
void multiply()
{
cin>>x;
cin>>y;
z=x*y;
cout<<"The multiplication is:"<<z<<endl;
}
void divide()
{
cin>>x;
cin>>y;
z=x/y;
cout<<"The division is:"<<z<<endl;
}
};
int main()
{
cout<<"Hello User!"<<endl;
char Name[23];
cout<<"Enter your name:";
cin>>Name;
cout<<"Hy "<<Name<<endl;
cout<<"Calculator:"<<endl;
Calculator maths;
cout<<"Enter two numbers to Add:"<<endl;
maths.add();
cout<<"Enter two numbers to Substract:"<<endl;
maths.substract();
cout<<"Enter two numbers to Multiply:"<<endl;
maths.multiply();
cout<<"Enter two numbers to Divide:"<<endl;
maths.divide();
}
You are missing std:: qualifiers whenever you use cin, cout, or endl. Either use std::cout, std::cin and std::endl or include using namespace std; in the beginning of your file.

Answer 3

You need to pass the values to the function Calculate. Variables x, y, z and function are not accessible outside the class and also u need a return type to the function so that you can get the output from the function Calculate.
class Calculator
{
public:
int x;
int y;
int z;
char function;
int Calculate(int main_x,int main_y,char main_function)
{
x= main_x;
y=main_y;
function = main_function;
if(function=='+')
{z=x+y; return z;}
else if(function=='-')
{z=x-y; return z;}
else if(function=='*')
{z=x*y; return z;}
else if(function=='/')
{z=x/y; return z;}
else
{cout<<"Wrong Function!!!"; return 0;}
}
};
void main()
{
clrscr();
int main_x,main_y,main_z;
char main_function;
Calculator working;
cout<<"Welcome!"<<endl;
cout<<"Enter your first number:"<<endl;
cin>>main_x;
cout<<"Enter your function:"<<endl;
cin>>main_function;
cout<<"Enter your second number:"<<endl;
cin>>main_y;
main_z = working.Calculate(main_x,main_y,main_function);
cout<<"Your Result is:"<<main_z<<endl;
getch();
}

Answer 4

Error is coming because you are trying to access class member variable x, y, z from outside in the main() where x, y, z is not declared.
In order to calculate() work correctly x, y, z should get correct value, in your case these variable has garbage value.

Answer 5

This is successful compiles version of your code.
#include <iostream>
#include <cmath>
#include <cstring>
using namespace std;
class Calculator
{
public:
int x;
int y;
int z;
char function;
void Calculate()
{
if(function=='+')
{z=x+y;}
else if(function=='-')
{z=x-y;}
else if(function=='*')
{z=x*y;}
else if(function=='/')
{z=x/y;}
else
{cout<<"Wrong Function!!!"<<endl;}
}
};
int main()
{
Calculator working;
cout<<"Welcome!"<<endl;
cout<<"Enter your first number:"<<endl;
cin>>working.x;
cout<<"Enter your function:"<<endl;
cin>>working.function;
cout<<"Enter your second number:"<<endl;
cin>>working.y;
working.Calculate();
cout<<"Your Result is:"<<working.z<<endl;
return 0;
}