如何在多维数组中使用键

Question

How to create an array which consists of categories and its sub categories.

Example:

Fruit
  --> Apple
  --> Banana

Car
  --> Civic
  --> Vitz

Drinks
 --> Pepsi
 --> Dew

So it becomes a complete one array.

Note: I don't want to use any collections eg lists,dictionary etc.

Answer 1

If you are restricted to using only arrays, then you could do something like:

object[][] arr = new object[3][];
arr[0] = new object[2];
arr[0][0] = "Fruit";
arr[0][1] = new string[2] { "Apple", "Banana" };
arr[1] = new object[2];
arr[1][0] = "Car";
arr[1][1] = new string[2] { "Civic", "Vitz" };
arr[2] = new object[2];
arr[2][0] = "Drinks";
arr[2][1] = new string[2] { "Pepsi", "Dew" };

Then to iterate through:

for (int i = 0; i < 3; i++)
{
    StringBuilder line = new StringBuilder();
    line.Append((string)arr[i][0] + ": ");
    string[] subs = (string[])arr[i][1];
    for (int j = 0; j < 2; j++)
    {
       line.Append(subs[j] + "; ");
    }
    MessageBox.Show(line.ToString());
}

Note because this uses a jagged array (AKA array of arrays), you can have different numbers of sub-categories. Then to iterate through the sub-categories you would need to use the count.

Answer 2

Create an interface called arrayobject then create the class fruit,car and drinks then implement the interface and make an array of the interface

something like

public interface arrayobject 
{
    string description();
}
class Fruit:arrayobject
{
    public string fruittype;
    public Fruit(string type)
    {
        fruittype = type;
    }

    public string description()
    {
        return fruittype;
    }
}
class Car : arrayobject
{
    public string Cartype;
    public Car(string type)
    {
        Cartype = type;
    }

    public string description()
    {
        return Cartype;
    }
}

now you can make a array of the arrayobject

arrayobject[] mylist = new arrayobject[2];
mylist[0] = new Fruit("banana");
mylist[1] = new Car("my Ford");