CODEWITHSUNDEEP
c#listcontains
Guillaume Slashy
Guillaume Slashy

Reputation: 3624

Does a List<T> Contains a property of T?

I got this List :

private static List<Type> _AbstractTypes = new List<Type>();

and later in my project I got a string that corresponds to a Type.FullName. The thing is that I'd like to check if my string is contained in my List but I don't manage to avoid a loop usable :( Im looking for something like :

_AbstractTypes.FullName.Contains(myString)

I am absolutely aware that my previous code is not compilable at all but that's the sort of thing im looking for ! Thanks in advance for any help

Upvotes: 0

Views: 164

Answers (6)

Marcin Deptuła
Marcin Deptuła

Reputation: 11977

You can use Linq, but we are talking about loop-less construct here only, the code under the hood must do a loop, if you want to do it better, you could use HashSet<T>.

Linq code could look like this:

_AbstractTypes.Any(t => t.FullName == myString);

HashSet<Type> code could look like this:

var types = new HashSet<Type>();
types.Add(typeof(int)); //Fill it with types
types.Add(typeof(double));

//Check by getting types from their string name, you could of course also cache those types
Console.WriteLine("Contains int: " + types.Contains(Type.GetType(intName))); //True
Console.WriteLine("Contains float: " + types.Contains(Type.GetType(floatName))); //False

Upvotes: 6

Fischermaen
Fischermaen

Reputation: 12468

I think you can find out if a type is contained in your list that way:

if (_AbstractTypes.Contains(typeof(string)))
{
    // Do Something
}

Upvotes: 0

Petar Ivanov
Petar Ivanov

Reputation: 93080

You can't avoid looping.

You can do (with looping behind the scenes):

bool check = _AbstractTypes.Any(item => item.FullName == myString);

Upvotes: 0

Doron Yaacoby
Doron Yaacoby

Reputation: 9770

You probably want something like this:

_AbstractTypes.Any(t=>t.FullName.Contains(myString))

Upvotes: 0

Steve B
Steve B

Reputation: 37710

This code :

bool result = _AbstractTypes.Any(t=>t.FullName == myString);

Should do the job.

It will test the predicate against all type until one is satisfied (true is returned), or none (false is returned).

Upvotes: 1

escargot agile
escargot agile

Reputation: 22389

If the list contains elements, you can do something like _AbstractTypes.First().GetType().

Upvotes: 0

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