Enumerable.Take<TSource> Method

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function Take(Of TSource) ( _
    source As IEnumerable(Of TSource), _
    count As Integer _
) As IEnumerable(Of TSource)

public static IEnumerable<TSource> Take<TSource>(
    this IEnumerable<TSource> source,
    int count
)

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

Remarks

This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

Take<TSource> enumerates source and yields elements until count elements have been yielded or source contains no more elements.

If count is less than or equal to zero, source is not enumerated and an empty IEnumerable<T> is returned.

The Take<TSource> and Skip<TSource> methods are functional complements. Given a sequence coll and an integer n, concatenating the results of coll.Take(n) and coll.Skip(n) yields the same sequence as coll.

In Visual Basic query expression syntax, a Take clause translates to an invocation of Take<TSource>.

Examples

The following code example demonstrates how to use Take<TSource> to return elements from the start of a sequence.

      ' Create an array of Integer values that represent grades.
      Dim grades() As Integer = {59, 82, 70, 56, 92, 98, 85}

      ' Get the highest three grades by first sorting
      ' them in descending order and then taking the
      ' first three values.
      Dim topThreeGrades As IEnumerable(Of Integer) = _
          grades _
          .OrderByDescending(Function(grade) grade) _
          .Take(3)

      ' Display the results.
      Dim output As New System.Text.StringBuilder("The top three grades are:" & vbCrLf)
      For Each grade As Integer In topThreeGrades
         output.AppendLine(grade)
      Next
      outputBlock.Text &= output.ToString() & vbCrLf

      ' This code produces the following output:
      '
      ' The top three grades are:
      ' 98
      ' 92
      ' 85

      int[] grades = { 59, 82, 70, 56, 92, 98, 85 };

      IEnumerable<int> topThreeGrades =
          grades.OrderByDescending(grade => grade).Take(3);

      outputBlock.Text += "The top three grades are:" + "\n";
      foreach (int grade in topThreeGrades)
      {
         outputBlock.Text += grade + "\n";
      }
      /*
       This code produces the following output:

       The top three grades are:
       98
       92
       85
      */

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.

See Also

Reference