invalid types ‘double[int]’ for array subscript

[roncriss]

hi guys
i am developing a calculator through a certain tutorial and i came up with the following errors

roncriss@linux-box:~/Desktop/linux calculator> g++ main.cpp
In file included from main.cpp:4:
calculator.cpp: In member function ‘int Calc::Operation(std::string)’:
calculator.cpp:47: error: invalid types ‘double[int]’ for array subscript
calculator.cpp:49: error: invalid types ‘double[int]’ for array subscript
calculator.cpp:55: error: expected `}' before ‘else’
calculator.cpp:57: error: ‘else’ without a previous ‘if’
calculator.cpp:59: error: ‘else’ without a previous ‘if’
calculator.cpp:62: error: invalid types ‘double[int]’ for array subscript
calculator.cpp: At global scope:
calculator.cpp:65: error: expected unqualified-id before ‘else’
calculator.cpp:71: error: expected declaration before ‘}’ token
roncriss@linux-box:~/Desktop/linux calculator>


here are my source code:

calculator.cpp

class Calc
{
public:
Calc();
double Number; //Answer
int Operation(string); //work with client code
int stack_spot; //hold the spot in the stack
private:
double s2f(string); //converts from string to double
double stack; // stack that hold data
void Add();
void Sub();
void Mult();
void Div();
void Sqrt();
void Equal();
void Clear();
double SquareRoot(double);
double Abs(double);
};
/***************************************************************************/
/***************************************************************************/
/***************************************************************************/
Calc :: Calc()
{
stack_spot = 0;
Number = 0;
}
/***************************************************************************/
/***************************************************************************/
/***************************************************************************/
int Calc :: Operation (string n)
{
if( n == "sqrt")
{
cout<<stack_spot<<endl;
Sqrt();
stack_spot = 1;
cout<<stack_spot<<endl;
return -1;
}
else if (n == "Clear")
{
Clear();
return -1;
}
else if (stack_spot == 0)
{
stack[0] = s2f(n);
stack_spot++;
Number = stack[0];
}
else if (stack_spot == 1)
{
if (n == "+");
n == "1";
else if (n == "-");
n == "2";
else if (n == "*");
n == "3";
else if (n == "/");
n == "4";

stack[stack_spot] =s2f(n);
stack_spot++;
}
else if(stack_spot == 2)
{
stack[2] == s2f(n);
Equal ();
stack_spot = 1;
}
}
/*********************************************************** ****************/
/***************************************************************************/
/***************************************************************************/
void Calc :: Sqrt()
{


}
/*********************************************************** ****************/
/***************************************************************************/
/***************************************************************************/
void Calc :: Clear()
{

}
/*********************************************************** ****************/
/***************************************************************************/
/***************************************************************************/
void Calc :: s2f(string s)
{

}
/*********************************************************** ****************/
/***************************************************************************/
/***************************************************************************/
void Calc :: Equal()
{

}
/*********************************************************** ****************/
/***************************************************************************/

and main.cpp

#include<iostream>
#include <stdlib.h>
using namespace std;
#include "calculator.cpp"

int main()
{
system ("clear");
Calc a;
string s ="q";
while (s !="exit")
{
cout<<"MATH:>";
cin>> s;
a.Operation(s);
}
return 0;

}

is anyone can help me with this?

[jsmith]

Please use code tags when posting code.

First, you are using the "stack" member as an array in Operation() but it is defined
as a double, not an array of doubles.

Second, you have stray semicolons at the end of some of your if() statements:

if (n == "+"); //<- remove semicolon
n == "1";
else if (n == "-");  //<- remove semicolon
n == "2";
else if (n == "*"); //<- remove semicolon
n == "3";
else if (n == "/"); //<- remove semicolon
n == "4";

[roncriss]

Thanks man you have been very helpful!
i discovered other errors also through your help,now i can compile without problem.