Method ForEach

ForEach<TSource>(IEnumerable<TSource>, Action<TSource>)

Immediately executes the given action on each element in the source sequence.

Declaration

public static void ForEach<TSource>(this IEnumerable<TSource> source, Action<TSource> action)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence of elements
Action<TSource>	action	The action to execute on each element

Type Parameters

Name	Description
TSource	The type of the elements in the sequence

Remarks

This operator executes immediately.

Examples

The following code example demonstrates how to immediately execute an action on every element of a sequence using ForEach.

var sequence = Enumerable.Range(1, 5);

// Fold a sequence into a single value.
sequence
    .ForEach(x => Console.Write($"{x}, "));

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

Exceptions

Type	Condition
ArgumentNullException	source or action is null.

ForEach<TSource>(IEnumerable<TSource>, Action<TSource, int>)

Immediately executes the given action on each element in the source sequence. Each element's index is used in the logic of the action.

Declaration

public static void ForEach<TSource>(this IEnumerable<TSource> source, Action<TSource, int> action)

Parameters

Type	Name	Description
IEnumerable<TSource>	source	The sequence of elements
Action<TSource, int>	action	The action to execute on each element; the second parameter of the action represents the index of the source element.

Type Parameters

Name	Description
TSource	The type of the elements in the sequence

Remarks

This operator executes immediately.

Examples

The following code example demonstrates how to immediately execute an action on every element of a sequence using ForEach.

var sequence = Enumerable.Range(1, 5);

// Fold a sequence into a single value.
sequence
    .ForEach((x, i) => Console.Write($"({x}, {i}), "));

// This code produces the following output:
// (1, 0), (2, 1), (3, 2), (4, 3), (5, 4), 

Exceptions

Type	Condition
ArgumentNullException	source or action is null.