Dynamic Object Name

Hi all, looking for a little help with dynamic object names.

Eg, i have a class for students. When the system is run, the user will be asked how many students they require, the program can then create X instances of the student class,

student1, student2... studentX etc.

Im just wondering how todo this. Is Student student[i](); correct for a constructor? If not, how do I do it ?

Cheers
Taz

the constructor should remain "standard":
Student();

to create the objects:

thank you very much young sir, will report back when i balls it up

Cheers
Taz

one thing, I need to pass 2 arguments to my constructor.

So does...


become

right, on compilng the following code I get the following errors..



Errors:


Side note. The class works when calling normally, eg Students students(5,3);

Try declaring your array like this:

From your error message it looks like you don't have a constructor defined that takes two arguments, but that is the way you would call the constructor. A constructor is like any other function except it doesn't and can't have a return type, and when you call any function, the parameters must match up with a function definition.

student[i]=new Student(MY ARGUMENTS?);
---------------

Student student[];******what size array did you create here?

for (i=0;i<students_number;i++) {
student[i]=new Student();
}

Hi guys, the following fixed it, required pointers. Note, student is now monkey

Regards

7stud was right. some clarifications.
What you are trying to do, as you probably know, is to dynamically allocate an array of

Student.
You have to use pointers since you don't know the size of the array.

before that you have some problems with the constructor.
let's take the following class:


let's say you want to retrieve the number of the students, as well as the IDs, from the user

and than construct these instances.
This is the wrong way:


why? because when you try to allocare the "new Student[..]" the program tries to construct

these instances.

you have to possibilities as far as I know:
1. Use pointer to pointer (I will explain)
2. Add a function "Create(int i, int j)" and empty the constructor.

Explaination:
1. Instead of allocating an array of students we allocate an array of pointers to Student


2. Add Create(int, int) that does the same thing as the constructor. make the constructor do

NOTHING and do the following:

Your solution is good only if the number of monkeys is constant - but if you want to get this and the other values from the user it wont work i suspect.

>> 2. Add Create(int, int) that does the same thing as the constructor. make the constructor do nothing
Or, you could use my example posted above and use the constructor just fine. BTW I tested my example with g++ before posting it here .

It would work - but i'm not sure it will satisfy all the requirements:
1. The number of Elements is CONSTANT and not dynamic
2. What if you want to construct the each element with different values?!

>> 1. The number of Elements is CONSTANT and not dynamic
Nope, you can get num_students from user input.

>> 2. What if you want to construct the each element with different values?!
Then you'd have to have a constructor with no arguments and set the values inside a for loop, like your example did .

I have checked it on VC++ and you cannot get num_students from the user.
if you have succeeded please post the code - prove me wrong.
(the previous code you posted doesn't work)

Scorpions4ever is right, as he/she well knows, and has always been the case in my experience. It's pretty trivial to prove, but here's an example anyway (using int as the type rather than Student) compiled and run in VC++6:



Normally, an array size must be determinable at compile time, so the memory can be set aside, however when you're allocating memory dynamically at run time, the size of an array doesn't need to be known until run time.