Create instance on class programatically

what is the correct procedure to automate instantiation of a class ?

if i create a class

Code:

---


class animal()
{
int age { get; set; }  // private by default
int weight { get; set; }
int counter { get; set; }

public animal() //default constructor
{
age = 20;
weight = 10;
}

public void set_age(int new_age)
{
age = new_age;
}

public void set_weight(int new_weight)
{
weight = new_weight;
}

---

now i want to create an infinite number of animals in my code.

i figure it has to use an array to track objects

animal[i].set_age(int 30);
animal[i].set_weight(int 40);

but how do i implement this so i instantiate a new animal anywhere and the class will increment its index and create it ( and keep count so i can check) ?

i have seen this somewhere but think i lost the link :(

cheers

Code:

---

List<Animal> animals = new List<Animal>();
for (int i = 0; i < 1000; ++i)
{
  animals.Add(new Animal());
}
for (int i = 0; i < 1000; ++i)
{
  animals[i].set_age(30);
  animals[i].set_weight(30);
}

---

There are many options. You can create an normal array or you can use an list

Code:

---

animal [] myAnimalArray = new animal[5];
for(int i = 0; i < myAnimalArray.length; i++)
{
  myAnimalArray[i] = new animal();
}//for

---

Code:

---

System.Collections.Generic.List<animal> myList = new System.Collections.Generic.List<animal>();
for (int i = 0; i < 5; i++)
{
    myList.Add(new animal());
}//for

int count = myList.Count;

---

thanks guys but both of these rely on having a predetermined number to start.

i < 1000
new animal[5]

but i want to be able to jst stick in my code

new_animal()

and have the code do something along the lines of

Code:

---

public partial class Form1 : Form
    {
        Person mypeople = new Person();
        Person []newpeople;

        public Form1()
        {
            InitializeComponent();
            mypeople.new_person(newpeople);
        }
}

---

Code:

---

namespace Class_test
{
    public class Person
    {
        private string name { get; set; }
        private string lang { get; set; }
        private int age { get; set; }
        private int person_count { get; set; }

        public Person()
        {
            name = "james";
            lang = "english";
            age = 25;
            MessageBox.Show("constructor called");
        }

        public Person new_person(Person []newperson)
        {
        newperson[new_person++] = new Person(); //<-- creates instance here but returns a null reference

        return newperson[0];
        }
}

---

i have seen this done in some code where they called a constructor to increment a count then created an instance of their class from the value of that count.

i cant remember whether it all happened inside the class, or 2 seperate classes/constructors tbh.

}
}

first of all, the code you posted is invalid syntax. you can't increment a method, nor can you increment an array.

second, using a List<> allows you to have as many animals as you'd like assuming you have the available memory.

Code:

---

namespace Class_test
{
    public partial class Form1 : Form
    {
        int[]newpeople = new int[10];
        int I = 0;

        public Form1()
        {
            InitializeComponent();
           
            newpeople[I++] = 10;
            newpeople[I++] = 20;
            newpeople[I++] = 30;
        }
    }
}

---

is it just the way i have the previous code - because the array increment works fine ?

Code:

---

List<Animal> animals = new List<Animal>();

// ... Somewhere else in our code ...

Animal temp = new Animal();
temp.set_age(30);
animals.Add(temp);

---

In that way, you can add however many animals you want, just make a new animal and call .Add() to put it in the list.