How can I use a string to create a class object?

[bkharoud]

I wanted to create a new class object and I want to name it from a string. Something like this:

string name = "Mike";
Customers name;  //to create a new object in customer class using the name string 

Is there any way to do this?

[MiiNiPaa]

Use constructors:

class Customers
{
    std::string str;
public:
    Customers(const std::string& s) : str(s) {}
}

int main()
{
    std::string name = "Mike";
    Customers m(name);
    Customers j("John");
}

[poteto]

^ Or arguments to be specific.

[bkharoud]

Sorry, I still don't understand. What exactly is it that the constructor does? Is it the "m(name)" part?

[MiiNiPaa]

m is an object of class Customers, created with variable name as parameter (as you can see it is used to initialize some internals.)

j is an object of class Customers, created with string literal "John" as parameter.

http://www.learncpp.com/cpp-tutorial/85-constructors/
http://www.cplusplus.com/doc/tutorial/classes/

[bkharoud]

Thanks for the reply.

What I want to do is to take the string and make it the name of the object. For example if I had a program where the user inputs a customer's name and I then need to make a class object that is named the same name the user input. In the top example, instead of creating m or j as an object I need to create the text in the string as an object.

[MiiNiPaa]

Why do you need that? How do you intend to refer to this object later if you do not know its actual name?

[bkharoud]

The customer example was just a simple way to show what I'm talking about, but what I'm working on is a program that takes in a bunch of files and I want to store info from each file into it's own class object, so that later on I can display it in my program. When a new file is input, the program adds the names of them to a listbox. When I select something in the listbox I want it to look in the class object that was made using name of the file in order to load the details of the specific file.

[MiiNiPaa]

Store a filename alongside your classes.

Like:

struct file_content
{
    std::string file;
    Customers customers;
};

//...
std::vector<file_content> data;

std::string filename = ask_user_for_string();
file_content temp;
temp.file = filename;
temp.customers = load_from_file(filename);
data.push_back(temp);

Or use standard std::pair to avoid defining own structure.

[LB]

I would recommend a std::map<std::string, blah>

[bkharoud]

For the struct example, how would I know which data to get when a new item is selected in the listbox?

Is there somehow a way to rename a class object after it has been declared?

[JLBorges]

Something along these lines:

struct info
{
    explicit info( std::string file_name )
    {
        // open file
        // read and store into member variables

    }

    // ...

    static std::map< std::string, info > look_up_table ;

    static info info_by_name( std::string file_name )
    {
        auto iter = look_up_table.find(file_name) ;

        if( iter == look_up_table.end() ) // not found; info was not loaded
            iter = look_up_table.insert( { file_name, info(file_name) } ).first ; // create info, add to look up table

        return iter->second ; // return info
    }
};