Does a List Contains a property of T?

Question

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

So you don't want to use a loop? or you just want help implementing a loop? Because i think with a foreach loop you will get the desired result. — stackr, Dec 07 '11 at 08:56

Marcin Deptuła · Accepted Answer · 2011-12-07T09:01:42.337

6

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

edited Dec 07 '11 at 09:01

answered Dec 07 '11 at 08:54

Marcin Deptuła

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_AbstractTypes.Any(t => t.FullName == myString); is perfect :) By "no loop" I was meaning not something with some old-school looking code and your answer is what I was looking for ;) thx! – Guillaume Slashy Dec 07 '11 at 09:04
@GuillaumeSlashy Linq looks modern and cool, so it should do the trick of not looking old-school :-) – Marcin Deptuła Dec 07 '11 at 09:06
yep, thats exactly what I was looking for :> – Guillaume Slashy Dec 07 '11 at 09:09

score 1 · Answer 2 · answered Dec 07 '11 at 08:56

1

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).

answered Dec 07 '11 at 08:56

Steve B

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score 0 · Answer 3 · answered Dec 07 '11 at 08:54

0

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

answered Dec 07 '11 at 08:54

Ilya Kogan

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score 0 · Answer 4 · answered Dec 07 '11 at 08:56

0

You probably want something like this:

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

answered Dec 07 '11 at 08:56

Doron Yaacoby

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score 0 · Answer 5 · answered Dec 07 '11 at 08:56

0

You can't avoid looping.

You can do (with looping behind the scenes):

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

answered Dec 07 '11 at 08:56

Petar Ivanov

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score 0 · Answer 6 · answered Dec 07 '11 at 08:59

0

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

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

answered Dec 07 '11 at 08:59

Fischermaen

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Does a List Contains a property of T?

6 Answers6