Partager via

  • Article

Enumerable.Min<TSource> Method (IEnumerable<TSource>)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Returns the minimum value in a generic sequence.

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

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function Min(Of TSource) ( _
    source As IEnumerable(Of TSource) _
) As TSource

public static TSource Min<TSource>(
    this IEnumerable<TSource> source
)

Type Parameters

  • TSource
    The type of the elements of source.

Parameters

Return Value

Type: TSource
The minimum value in the sequence.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IEnumerable<TSource>. When you use instance method syntax to call this method, omit the first parameter.

Exceptions

Exception Condition
ArgumentNullException

source is nulla null reference (Nothing in Visual Basic).

Remarks

If type TSource implements IComparable<T>, this method uses that implementation to compare values. Otherwise, if type TSource implements IComparable, that implementation is used to compare values.

If TSource is a reference type and the source sequence is empty or contains only values that are nulla null reference (Nothing in Visual Basic), this function returns nulla null reference (Nothing in Visual Basic).

In Visual Basic query expression syntax, an Aggregate Into Min() clause translates to an invocation of Min.

Examples

The following code example demonstrates how to use Min<TSource>(IEnumerable<TSource>) to determine the minimum value in a sequence of IComparable<T> objects.

   ' This class implements IComparable 
   ' and has a custom 'CompareTo' implementation.
   Class Pet
      Implements IComparable(Of Pet)

      Public Name As String
      Public Age As Integer

      ''' <summary>
      ''' Compares this Pet's age to another Pet's age.
      ''' </summary>
      ''' <param name="other">The Pet to compare this Pet to.</param>
      ''' <returns>-1 if this Pet's age is smaller,
      ''' 0 if the Pets' ages are equal,
      ''' or 1 if this Pet's age is greater.</returns>
      Function CompareTo(ByVal other As Pet) As Integer _
          Implements IComparable(Of Pet).CompareTo

         If (other.Age > Me.Age) Then
            Return -1
         ElseIf (other.Age = Me.Age) Then
            Return 0
         Else
            Return 1
         End If
      End Function
   End Class

   Sub MinEx3()
      ' Create an array of Pet objects.
      Dim pets() As Pet = {New Pet With {.Name = "Barley", .Age = 8}, _
                           New Pet With {.Name = "Boots", .Age = 4}, _
                           New Pet With {.Name = "Whiskers", .Age = 1}}

      ' Determine the "minimum" pet in the array,
      ' according to the custom CompareTo() implementation.
      Dim min As Pet = pets.Min()

      ' Display the result.
      outputBlock.Text &= "The 'minimum' pet is " & min.Name & vbCrLf
   End Sub

   ' This code produces the following output:
   '
   ' The 'minimum' pet is Whiskers


      /// <summary>
      /// This class implements IComparable in order to 
      /// be able to compare different Pet objects.
      /// </summary>
      class Pet : IComparable<Pet>
      {
         public string Name { get; set; }
         public int Age { get; set; }

         /// <summary>
         /// Compares this Pet's age to another Pet's age.
         /// </summary>
         /// <param name="other">The Pet to compare this Pet to.</param>
         /// <returns>-1 if this Pet's age is smaller, 
         /// 0 if the Pets' ages are equal, or 
         /// 1 if this Pet's age is greater.</returns>
         int IComparable<Pet>.CompareTo(Pet other)
         {
            if (other.Age > this.Age)
               return -1;
            else if (other.Age == this.Age)
               return 0;
            else
               return 1;
         }
      }

      public static void MinEx3()
      {
         Pet[] pets = { new Pet { Name="Barley", Age=8 },
                            new Pet { Name="Boots", Age=4 },
                            new Pet { Name="Whiskers", Age=1 } };

         Pet min = pets.Min();

         outputBlock.Text += String.Format(
             "The 'minimum' animal is {0}.",
             min.Name) + "\n";
      }

      /*
       This code produces the following output:

       The 'minimum' animal is Whiskers.
      */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.