Array List in C# without a loop - c#-4.0

Question

I like to know how to initialise the array without the loops like for, foreach or any LINQ.
From the following code, need to find under 2m length cars within .Netframework using console application.
{
ArrayList = CarType new ArrayList();
CarType.Add(new CarList("Ford"));
((CarList)CarType[0]).Cars.Add(new Car("Focus", 2));
((CarList)CarType[0]).Cars.Add(new Car("Fiesta", 1));
CarType.Add(new CarList("Peugeout"));
((CarList)CarType[1]).Cars.Add(new Car("206", 1));
((CarList)CarType[1]).Cars.Add(new Car("407", 2));
RemoveLargeCars(CarType);
}
public static ArrayList RemoveLargeCars (ArrayList CarType)
{
//Array List should be here
return CarType;
}
It has got two classes as follows.
class Car
{
public string name;
public float length;
public Car(string newName, float newLength)
{
this.name = newName;
this.length = newLength;
}
}
Class CarList
{
public string CarType;
public ArrayList Pipes;
public CarList(string newCarType)
{
carType = newCarType;
Cars = new ArrayList();
}
}
Can you please let me know how to solve this.
Thanks in advance.

Answer 1

Use the static Adapter method on ArrayList
CarType = ArrayList.Adapter(CarList);
But that probably uses a loop internally, you can't get away from them, but at least this hides them.

Answer 2

Well, first of all you should use the generic list type List<T> instead of ArrayList, that will make the code simpler. (And best practive recommends properties rather than public fields):
class Car {
public string Name { get; set; }
public float Length { get; set; }
public Car(string newName, float newLength) {
Name = newName;
Length = newLength;
}
}
class CarList {
public string CarType { get; set; }
public List<Car> Cars { get; set; }
public CarList(string newCarType, List<Car> newCars) {
CarType = newCarType;
Cars = newCars;
}
public CarList(string newCarType) : this(newCarType, new List<Car>()) {}
}
Now use a List<CarList>:
List<CarList> CarType = new List<CarList>();
CarList ford = new CarList("Ford");
CarType.Add(ford);
ford.Cars.Add(new Car("Focus", 2));
ford.Cars.Add(new Car("Fiesta", 1));
CarList peugeot = new CarList("Peugeout");
CarType.Add(peugeot);
peugeot.Cars.Add(new Car("206", 1));
peugeot.Cars.Add(new Car("407", 2));
List<CarList> smallCars = RemoveLargeCars(CarType);
You can use extension methods to easily filter out cars based on a condition:
public static List<CarList> RemoveLargeCars(List<CarList> CarType) {
return CarType.Select(
t => new CarList(t.CarType, t.Cars.Where(c => c.Length < 2f).ToList()
) .ToList();
}
Note that the method doesn't change the original list, but creates a new list.