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Contract.Exists(T) Method (IEnumerable(T), Predicate(T))

Determines whether an element within a collection of elements exists within a function.

Namespace:  System.Diagnostics.Contracts
Assemblies:   mscorlib (in mscorlib.dll)
  System.Diagnostics.Contracts (in System.Diagnostics.Contracts.dll)

static member Exists : 
        collection:IEnumerable<'T> * 
        predicate:Predicate<'T> -> bool

Type Parameters


The type that is contained in collection.


Type: System.Collections.Generic.IEnumerable(T)

The collection from which elements of type T will be drawn to pass to predicate.

Type: System.Predicate(T)

The function to evaluate for an element in collection.

Return Value

Type: System.Boolean
true if and only if predicate returns true for any element of type T in collection.


collection or predicate is a null reference (Nothing in Visual Basic).

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Portable Class Library

Supported in: Portable Class Library
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