Initializing a private array member

How do i initialize array groups

Code:

---

class GroupManager
{
private:

        typedef std::vector<FleetGroup> Categories;
        typedef Categories::iterator GroupIterator;

public:

        GroupManager();

        GroupIterator find();
        void ReadGroupFile();
        void AddNewGroup();
        void EditGroup();
        void ViewAllGroups();
        void ReadGroups();
        void ViewAGroup();
        void SaveGroupToFile();

private:
        Categories fleet;
        std::string groups[MAX_GRP];
};

// MY ATTEMPT
GroupManager::GroupManager() :
groups = { "a", "b", "c", "d", "f", "o", "z" }
{};

//ERROR!!

---

Do this in the constructor body. You need to use the copy algorithm, or a container that can take in a temporary array.

Nope.. you will have to do it the way you are trying to avoid doing.

Confusing answers ... :( can i have examples of your suggestions please

citizen was alluding to something like this:

Code:

---

GroupManager::GroupManager()
{
    std::string temp[] = { "a", "b", "c", "d", "f", "o", "z" };
    std::copy(temp, temp + sizeof(temp) / sizeof(temp[0]), groups);
}

---

Of course, you could also do it without a temporary array, but it would be more tedious:

Code:

---

GroupManager::GroupManager()
{
    groups[0] = "a";
    groups[1] = "b";
    groups[2] = "c";
    groups[3] = "d";
    groups[4] = "f";
    groups[5] = "o";
    groups[6] = "z";
}

---

Or, you could make it a static variable, in which case you can do exactly what you are doing now, but on a global scope. [which I think it correct anyways, as I doubt that the groups will actually change between different instances of the class - if they do, then you probably should have a more dynamic way to define what the groups are, for example reading the group codes from a file, and of course, you need a completely different way to initialize the groups array if you do that].

--
Mats

Quote:

---

Originally Posted by matsp

Or, you could make it a static variable, in which case you can do exactly what you are doing now, but on a global scope. [which I think it correct anyways, as I doubt that the groups will actually change between different instances of the class - if they do, then you probably should have a more dynamic way to define what the groups are, for example reading the group codes from a file, and of course, you need a completely different way to initialize the groups array if you do that].

--
Mats

---

The user should be able to add new groups, which will add to this array... It can only grow up to 26 letters [A-Z], well no car rental will ever have so many groups anyway ...

Initializing it means there's are already existing groups on the shop (the ones specified) .. But say one opens a new rental shop ... Then this array doesn't need to be initialized.. Well not sure about making it global :(

Is your application meant to handle multiple locations (offices) within one instance of the application? Or is it one instance of the application per office?

If it's one instance per office, it can still be a static list.

--
Mats

Quote:

---

Originally Posted by matsp

Is your application meant to handle multiple locations (offices) within one instance of the application? Or is it one instance of the application per office?

If it's one instance per office, it can still be a static list.

--
Mats

---

one per office

Quote:

---

Originally Posted by csonx_p

one per office

---

Ok, so you can still use a static list that is initialized by reading from a file. The file can be "prebuilt" for standard locations, and then added to as the location acquires "out of the ordinary" vehicles. Or, you could have a default set, that is hard-coded, and then added to by reading from a file.

Note that the only difference with a static member and non-static member is that the static member will be ONE for all instances of the class, and it's sort of like a "global variable", but only available inside the class.

--
Mats

Quote:

---

Originally Posted by matsp

Ok, so you can still use a static list that is initialized by reading from a file. The file can be "prebuilt" for standard locations, and then added to as the location acquires "out of the ordinary" vehicles. Or, you could have a default set, that is hard-coded, and then added to by reading from a file.

Note that the only difference with a static member and non-static member is that the static member will be ONE for all instances of the class, and it's sort of like a "global variable", but only available inside the class.

--
Mats

---

as in

Code:

---


....

private:

        static std::string groups[MAX_GRP];
};

GroupManager::GroupManager() :

readDefaultGroupNames()

{};

void GroupManager::readDefaultGroupNames()
{
        ifstream datain;
        datain.open (filename);

        int cnt=0;
        while( datain.fail() ) {
                datain >> groups[cnt++];
        }

        datain.close();
}

---

Quote:

---

Originally Posted by csonx_p

as in

Code:

---


....

private:

        static std::string groups[MAX_GRP];
};

GroupManager::GroupManager() :

readDefaultGroupNames()

{};

void GroupManager::readDefaultGroupNames()
{
        ifstream datain;
        datain.open (filename);

        int cnt=0;
        while( datain.fail() ) {
                datain >> groups[cnt++];
        }

        datain.close();
}

---

---

This gives an error ... readDefaultGroupNames() should't be a member, but when i remove iand make it a free or static function still complains :(

Quote:

---

Originally Posted by csonx_p

as in

Code:

---


....

private:

        static std::string groups[MAX_GRP];
};

GroupManager::GroupManager() :

readDefaultGroupNames()

{};

void GroupManager::readDefaultGroupNames()
{
        ifstream datain;
        datain.open (filename);

        int cnt=0;
        while( datain.fail() ) {
                datain >> groups[cnt++];
        }

        datain.close();
}

---

---

Is this a straight copy'n'paste? The red bits looks suspicious...

Edit: And the blue is most likely not what you wanted, right?
--
Mats

Quote:

---

Originally Posted by matsp

Is this a straight copy'n'paste? The red bits looks suspicious...

Edit: And the blue is most likely not what you wanted, right?
--
Mats

---

The red bit :( isn't this how you do static initialization in a constructor? Blue bit, yeah forgot the '!'