Method Insert

Insert<T>(IEnumerable<T>, IEnumerable<T>, int)

Inserts the elements of a sequence into another sequence at a specified index.

Declaration

public static IEnumerable<T> Insert<T>(this IEnumerable<T> first, IEnumerable<T> second, int index)

Parameters

Type	Name	Description
IEnumerable<T>	first	The source sequence.
IEnumerable<T>	second	The sequence that will be inserted.
int	index	The zero-based index at which to insert elements from second.

Returns

Type	Description
IEnumerable<T>	A sequence that contains the elements of first plus the elements of second inserted at the given index.

Type Parameters

Name	Description
T	Type of the elements of the source sequence.

Remarks

This method uses deferred execution and streams its results.

Examples

The following code example demonstrates how to insert one sequence into the middle of another sequence using Insert.

var first = Enumerable.Range(1, 5);
var second = Enumerable.Range(1, 5);
            
// Insert one sequence into another
var result = first
    .Insert(second, 2);
            
Console.WriteLine(string.Join(", ", result));

// This code produces the following output:
// 1, 2, 1, 2, 3, 4, 5, 3, 4, 5

Exceptions

Type	Condition
ArgumentNullException	first or second is null.
ArgumentOutOfRangeException	Thrown if index is negative.
ArgumentOutOfRangeException	Thrown lazily if index is greater than the length of first. The validation occurs when yielding the next element after having iterated first entirely.

Insert<T>(IEnumerable<T>, IEnumerable<T>, Index)

Inserts the elements of a sequence into another sequence at a specified index.

Declaration

public static IEnumerable<T> Insert<T>(this IEnumerable<T> first, IEnumerable<T> second, Index index)

Parameters

Type	Name	Description
IEnumerable<T>	first	The source sequence.
IEnumerable<T>	second	The sequence that will be inserted.
Index	index	The zero-based index at which to insert elements from second.

Returns

Type	Description
IEnumerable<T>	A sequence that contains the elements of first plus the elements of second inserted at the given index.

Type Parameters

Name	Description
T	Type of the elements of the source sequence.

Remarks

This method uses deferred execution and streams its results.

Examples

The following code example demonstrates how to insert one sequence into the middle of another sequence using Insert.

var first = Enumerable.Range(1, 5);
var second = Enumerable.Range(1, 5);
            
// Insert one sequence into another
var result = first
    .Insert(second, ^2);
            
Console.WriteLine(string.Join(", ", result));

// This code produces the following output:
// 1, 2, 3, 1, 2, 3, 4, 5, 4, 5

Exceptions

Type	Condition
ArgumentNullException	first or second is null.
ArgumentOutOfRangeException	Thrown if index is negative.
ArgumentOutOfRangeException	Thrown lazily if index is greater than the length of first. The validation occurs when yielding the next element after having iterated first entirely.