Calculator Problem

[Volestar]

Ok, I've been working on this for about 4 hours, but I cannot get it to work! I'm starting with a char, then I need it to become a const char so I can use strcmp in my if statements. If there's anything wrong in that idea, please tell me what I have to do. If there's nothing wrong there, here's my code:

//Simple calculator.
#include <iostream>
#include <cmath>
#include <string>
using namespace std;
int calculate(int,const char,int);

int main()
{
    using namespace std;
    int a,b;
    char operation[1];
    cout << "Operations: +, -, *, /" << endl;
    cout << "Number 1: ";
    cin >> a;
    cout << "Operation: ";
    cin >> operation[1];
    const char op[1] = "";
    strcpy(op[1],operation[1]);
    cout << "Number 2: ";
    cin >> b;
    cout << endl;
    cout << "The answer is " << calculate(a,op[1],b);
    cout << "Press any key to close this program.";
    system("pause > nul");
    return 0;
}

int calculate(int a, const char operation, int b)
{
    using namespace std;
    if(operation == "+")
    {
                 return a + b;
                 }
    if(operation == "-")
    {
                 return a - b;
                 }
    if(operation == "*")
    {
                 return a * b;
                 }
    if(operation == "/")
    {
                    return a / b;
                    }
}

Just so you know, I'm a newbie at C++, so I don't understand anything about maps. Please help!

[sheff_cc]

#include <iostream>
#include <cmath>
#include <string>
using namespace std;
int calculate(int,const char,int);
 
int main()
{
    using namespace std;
    int a,b;
    char operation[1];
    cout << "Operations: +, -, *, /" << endl;
    cout << "Number 1: ";
    cin >> a;
    cout << "Operation: ";
    cin >> operation[1];
    char op = operation[1];
    cout << "Number 2: ";
    cin >> b;
    cout << endl;
    cout << "The answer is " << calculate(a,op,b);
    cout << "\nPress any key to close this program.";
    system("pause > nul");
    return 0;
}
 
int calculate(int a,char operation, int b)
{
    using namespace std;
    if(operation == '+')
    {
                 return a + b;
                 }
    if(operation == '-')
    {
                 return a - b;
                 }
    if(operation == '*')
    {
                 return a * b;
                 }
    if(operation == '/')
    {
                    return a / b;
                    }
}

[sheff_cc]

The op just need to store one character,so you don't need to use char[],and to use strcpy().
For strcpy(char*,const char*),if you want use it,you must transform the proper arguments into the function.

[WaltP]

A one-character array is not a c-string. strcpy() only works on null-terminated strings. As sheff said, there is no need to define a 1-element array. Just define the value as a char and copy it to another char with =.

[EngSara]

the array has positions from 0 to size-1. so if u declare operation[1] then the array have one element which is operation[0] not operation[1].

[Volestar]

#include <iostream>
#include <cmath>
#include <string>
using namespace std;
int calculate(int,const char,int);
 
int main()
{
    using namespace std;
    int a,b;
    char operation[1];
    cout << "Operations: +, -, *, /" << endl;
    cout << "Number 1: ";
    cin >> a;
    cout << "Operation: ";
    cin >> operation[1];
    char op = operation[1];
    cout << "Number 2: ";
    cin >> b;
    cout << endl;
    cout << "The answer is " << calculate(a,op,b);
    cout << "\nPress any key to close this program.";
    system("pause > nul");
    return 0;
}
 
int calculate(int a,char operation, int b)
{
    using namespace std;
    if(operation == '+')
    {
                 return a + b;
                 }
    if(operation == '-')
    {
                 return a - b;
                 }
    if(operation == '*')
    {
                 return a * b;
                 }
    if(operation == '/')
    {
                    return a / b;
                    }
}

Thanks for the help! What if I wanted 2 characters, for example, **?

[WaltP]

Thanks for the help! What if I wanted 2 characters, for example, **?

Does this question have anything to do with your program? Or are you just asking?

What is it you really want to do?