Method Shuffle

Shuffle<T>(IEnumerable<T>)

Returns a sequence of elements in random order from the original sequence.

Declaration

public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source)

Parameters

Type	Name	Description
IEnumerable<T>	source	The sequence from which to return random elements.

Returns

Type	Description
IEnumerable<T>	A sequence of elements source randomized in their order.

Type Parameters

Name	Description
T	The type of source sequence elements.

Remarks

This method is implemented by using deferred execution. However, source will be consumed in it's entirety immediately when first element of the returned sequence is consumed.

Examples

The following code example demonstrates how to shuffle a sequence using Shuffle.

var sequence = Enumerable.Range(1, 10);

// Shuffle a sequence
var result = sequence.Shuffle();

Console.WriteLine(
    "[" +
    string.Join(", ", result) +
    "]");

// One possible random output is as follows:
// [10, 9, 3, 8, 1, 6, 2, 4, 7, 5]

Exceptions

Type	Condition
ArgumentNullException	source is null

Shuffle<T>(IEnumerable<T>, Random)

Returns a sequence of elements in random order from the original sequence. An additional parameter specifies a random generator to be used for the random selection algorithm.

Declaration

public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source, Random rand)

Parameters

Type	Name	Description
IEnumerable<T>	source	The sequence from which to return random elements.
Random	rand	A random generator used as part of the selection algorithm.

Returns

Type	Description
IEnumerable<T>	A sequence of elements source randomized in their order.

Type Parameters

Name	Description
T	The type of source sequence elements.

Remarks

This method is implemented by using deferred execution. However, source will be consumed in it's entirety immediately when first element of the returned sequence is consumed.

Examples

The following code example demonstrates how to shuffle a sequence using Shuffle.

var sequence = Enumerable.Range(1, 10);

// Shuffle a sequence
var result = sequence.Shuffle(new Random(10));

Console.WriteLine(
    "[" +
    string.Join(", ", result) +
    "]");

// This code produces the following output:
// [1, 4, 2, 6, 3, 9, 5, 7, 10, 8]

Exceptions

Type	Condition
ArgumentNullException	source or rand is null