I am busy learning D and I want to be able to use classes now. I am used to programming in C# where it does everything for you and you don't have to think about this kind of thing so I now have no idea how to compile a program from the command line that uses a class in another source file.

I have a source file called MyProgram.d which contains the main program and I have a file called MyClass.d that contains a class called MyClass. I want to be able to create an instance of MyClass in the main program but I don't know what to type to compile it the command line. This is what I have tried so far which doesn't work:

dmd MyProgram.d MyClass.d

Thanks in advance for your help.

Some Guy wrote:
> I am busy learning D and I want to be able to use classes now. I am
> used to programming in C# where it does everything for you and you
> don't have to think about this kind of thing so I now have no idea
> how to compile a program from the command line that uses a class in
> another source file.
> 
> I have a source file called MyProgram.d which contains the main
> program and I have a file called MyClass.d that contains a class
> called MyClass. I want to be able to create an instance of MyClass in
> the main program but I don't know what to type to compile it the
> command line. This is what I have tried so far which doesn't work:
> 
> dmd MyProgram.d MyClass.d
> 
> Thanks in advance for your help.

What error message are you getting? Did you remember to put module and import statements in your source files?

MyClass.d:

    module MyClass;

    class MyClass
    {
       ...
    }

MyProgram.d:

    module MyProgram;
    import MyClass;

    void main()
    {
        MyClass m = new MyClass;    // Example
        ...
    }

    ...

(The module statement in MyProgram.d isn't strictly necessary in this case, but personally I think it's good form to always declare the name of a module.)

-Lars

Thank you for your help. The problem was that I didn't know that you had to use the import statement to be able to use a class in another source file.

Some Guy:
> I am busy learning D and I want to be able to use classes now. I am used to programming in C# where it does everything for you and you don't have to think about this kind of thing so I now have no idea how to compile a program from the command line that uses a class in another source file.

The good thing of D is that with just a little push it can become as handy as C# in this regard :-) The LDC compiler may grow the ability to find and load modules by itself.
In the meantime you can use a tool like "bud" (or another one named rebuild) to do that for you. This is bud:
http://www.dsource.org/projects/build/wiki

Bye,
bearophile

On Tue, 2 Dec 2008 09:28:53 +0000 (UTC), Some Guy wrote:

> I am busy learning D and I want to be able to use classes now. I am used to programming in C# where it does everything for you and you don't have to think about this kind of thing so I now have no idea how to compile a program from the command line that uses a class in another source file.
> 
> I have a source file called MyProgram.d which contains the main program and I have a file called MyClass.d that contains a class called MyClass. I want to be able to create an instance of MyClass in the main program but I don't know what to type to compile it the command line. This is what I have tried so far which doesn't work:
> 
> dmd MyProgram.d MyClass.d
> 
> Thanks in advance for your help.

Seeing that you didn't show us your code, I took the liberty of writing some example code...

---------- myprogram.d ---------
module myprogram;

// Tell the compiler that this file needs to know
// about what is in the file 'myclass.d'
import myclass;

import std.stdio;    // Need this to use writefln();

void main()
{
    // Create an instance of the class.
    MyClass inst = new MyClass();

    // Invoke a method in the instance.
    writefln("First %s", inst.A_Method());


    // Create another instance of the class.
    MyClass yai = new MyClass(5);

    // Invoke a method in the instance.
    writefln("Second %s", yai.A_Method());
}
--------- end of file -------------


---------- myclass.d ---------
module myclass;
class MyClass
{
    int SomeAttribute;
    // A class constructor
    this()
    {
        SomeAttribute = 1;
    }

    // Another class constructor
    this(int InitData)
    {
        SomeAttribute = InitData;
    }


    // A method
    int A_Method()
    {
        return SomeAttribute;
    }

}
--------- end of file -------------


The line to compile these ...

   dmd myprogram myclass

When running the program 'myprogram' you should get ...

c:\>myprogram
First 1
Second 5

-- 
Derek Parnell
Melbourne, Australia
skype: derek.j.parnell