problems compiling a month class

Hey I could really use somebody's help in explaining what I did wrong to get compiler errors with a "month" class I wrote for school. I am new to C++ so it's probably just some silly error or I am trying to do something completely wrong. I am just trying to get this thing to compile so you needn't debug it. Anyway all help will be greatly appreciated. EDIT: Many of my errors concern the declaration of monthAbbrev, does anyone see what I am doing wrong with it?

Code:

---

#ifndef MONTH_H
#define MONTH_H

const short MAX_M = 12;
const short MAX_N = 4;

class Month
{
    short monthNum;
    const char monthAbbrev[MAX_M][MAX_N] =
    {
          "jan", "feb", "mar", "apr", "may",
          "jun", "jul", "aug", "sep", "oct",
          "nov", "dec"
    };
    void translate(const char[]);

public:
    Month();
    Month(const char name[]);
    Month(const short number);
    void input(void);
    void outputNumber(void) const;
    void outputName(void) const;
    Month nextMonth(void) const;
    bool compare(const char str1[], const char str2[]) const;
    short get_monthNum(void) const { return monthNum; }
    void set_monthNum(const short num) { monthNum = num; }
};

#endif

---

And the implementation

Code:

---

#include <iostream>
#include <cstring>
#include <cctype>
using namespace std;
#include "month.h"

Month::Month()
{
    monthNum = 1;
}
Month::Month(const char name[])
{
      translate(name);
}       
Month::Month(const short number)
{
    monthNum = number;
}
void Month::input(void)
{
    char name[MAX_N];
    cin >> monthNum;
    if(cin.fail()) //if fail must be a char
    {
          cin.clear();
          cin.getline(name, MAX_N); //get string
          name[MAX_N - 1] = '\0';
          translate(name); //translate name to set monthNum
    }
    return;
}
void Month::outputNumber(void) const
{
    cout << monthNum;
    return;
}
void Month::outputName(void) const
{
    cout << monthAbbrev[monthNum - 1];
    return;
}
Month Month::nextMonth(void) const
{
    Month temp(monthNum + 1);
    return temp;
}
bool Month::compare(const char str1[], const char str2[]) const
{
    bool same = false;
    short index = 0;
    while(index != (MAX_N) && !same)
    {
          if(tolower(str1[index]) == tolower(str2[index]))
          {
        same = true;
        while(index != (MAX_N) && same)
        {
            if(tolower(str1[index]) != tolower(str2[index]))
            {
                  same = false;
            }
            index++;
        }
            }
      }
    return same;
}
void Month::translate(const char[] name)
{
    for(short i = 0; i != MAX_M; i++)
    {
          if(compare(monthAbbrev[i], name))
          {
        monthNum = i;
          }
    }
    return;
}

---

I'm new to this forum also, so I hope I posted that code correctly and didn't break any of the forum's rules. BTW I posted all the code so you could maybe compile it and tell me what errors you get.

Ever thought putting these under private?

Code:

---

    short monthNum;
    const char monthAbbrev[MAX_M][MAX_N] =
    {
          "jan", "feb", "mar", "apr", "may",
          "jun", "jul", "aug", "sep", "oct",
          "nov", "dec"
    };
    void translate(const char[]);

---

About the problem that you got, I think it's because you can't initialize monthAbbrev in header file.

First of all, you have to declare the array as static const char. Next, look at this bit of code:

monthNum = number;

What then happens when the user enters 300023, and then the code executes:

cout << monthAbbrev[monthNum - 1];

Finally, why are you putting a string comparison function in a class? That makes no sense. Just use strcasecmp(s1, s2)[located in string.h], the function returns 0 if they match. If you can't/don't want to use that, at *least* make the function outside of the class.

Quote:

---

monthNum = number;

What then happens when the user enters 300023, and then the code executes:

cout << monthAbbrev[monthNum - 1];

---

Yup, input validation is important.

Quote:

---

Finally, why are you putting a string comparison function in a class? That makes no sense. Just use strcasecmp(s1, s2)[located in string.h], the function returns 0 if they match. If you can't/don't want to use that, at *least* make the function outside of the class.

---

You know what, many people never realize that built-in functions are there until someone mentions about them

I have a question thou,
why static const char?

You can't initialize variables within a class in the declaration:

Code:

---

struct foo {
int i = 0;
};

---

That obviously won't compile.

Thanks for you replies so far, they have helped. As for strcasecmp, yeah I didn't know if there was a case insensitive compare function in cstring, so I wrote one real quick. Also, I didn't write any bounds checking because, well I wasn't sure exactly how do handle it. If it is out of bounds should I just default to say january's monthNum and cout a message saying "month out of bounds"? I always put my error checking where I actually prompt the user so I can loop the prompt until they enter valid data. I don't know, anymore comments are more than welcome.

EDIT:

Alright so I deleted my compare function and added strcasecmp to translate so its body now looks like this

Code:

---

void Month::translate(const char[] name)
{
    bool success = false;
    for(short i = 0; i != MAX_M; i++)
    {
          if(!strcasecmp(MONTHS[i], name))
          {
                monthNum = i;
                success = true;
          }
    }
    if(!success)
    {
          monthNum = 1;
    }
    return;
}

---

Also I placed monthAbbrev as a global constant and renamed it
const char MONTHS[MAX_M][MAX_N] = ...
anyway if I call it static const as suggested will I still be able to access it in the implementation file? As for some of the other functions, I added bounds checking with a default of monthNum = 1 if out of bounds occurs. I also changed nextMonth so it will work properly (ie if monthNum = 12 it now resets to 1). Long story short I think I fixed everything that was mentioned so far, but now my compiler (VS.net if that matters) doesn't like the translate function as I get many syntax errors with it. I would like to keep it a private function, so is there a different way to declare and define private functions? I thought they were implemented the same way as public functions. Thanks again for your time.

Nevermind I got it, what a stupid error I was making. Sometimes I just have to walk away and come back and it is all so glaringly obvious. Thanks again for the help.