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c#.netcollections
sharptooth
sharptooth

Reputation: 170479

Which .net 3.5 collection to use for a variable-length array of objects of one type?

I need a .NET 3.5 class more or less equivalent to C++ std::vector:

earlier I used ArrayList and it is quite right except it stores object and I have to cast the retrieved objects to the right type and I can add just anything there and this makes compile-time type checking harder.

Is there anything like ArrayList but parameterized by contained type?

Upvotes: 0

Views: 490

Answers (2)

Jon Skeet
Jon Skeet

Reputation: 1499770

Sounds like you're after List<T>. For example, to create a list of integers:

List<int> integers = new List<int>();
integers.Add(5); // No boxing required
int firstValue = integers[0]; // Random access

// Iteration
foreach (int value in integers)
{
    Console.WriteLine(value);
}

Note that you may wish to expose such lists via IEnumerable<T>, ICollection<T> or IList<T> rather than via the concrete type.

You don't need .NET 3.5 for these - they were introduced in .NET 2 (which is when generics were introduced as a feature). In .NET 3.5, however, there's LINQ which makes working with sequences of any kind easier:

IEnumerable<int> evenIntegers = integers.Where(x => x % 2 == 0);

(and much more).

Upvotes: 5

Albin Sunnanbo
Albin Sunnanbo

Reputation: 47038

List<T>

Substitute T with your type.

Example

// Create an empty List<int>
List<int> numbers = new List<int>();
numbers.Add(4);

// Use the c# collection initializer to add some default values;
List<int> numbersWithInitializer = new List<int> { 1, 4, 3, 4 };

Upvotes: 4

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