IGrouping<'TKey, 'TElement>.Key Property


Gets the key of the IGrouping<'TKey, 'TElement>.

Namespace:   System.Linq
Assembly:  System.Core (in System.Core.dll)

abstract Key : 'TKey with get

Property Value

Type: TKey

The key of the IGrouping<'TKey, 'TElement>.

The key of an IGrouping<'TKey, 'TElement> represents the attribute that is common to each value in the IGrouping<'TKey, 'TElement>.

The following example demonstrates how to use the Key property to label each IGrouping<'TKey, 'TElement> object in a sequence of IGrouping<'TKey, 'TElement> objects. The GroupBy<'TSource, 'TKey>(IEnumerable<'TSource>, Func<'TSource, 'TKey>) method is used to obtain a sequence of IGrouping<'TKey, 'TElement> objects. The foreach in Visual C# or For Each in Visual Basic loop then iterates through each IGrouping<'TKey, 'TElement> object, outputting its key and the number of values it contains.

No code example is currently available or this language may not be supported.

Universal Windows Platform
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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