Export (0) Print
Expand All

List<T>.ForEach Method

Performs the specified action on each element of the List<T>.

Namespace:  System.Collections.Generic
Assemblies:   mscorlib (in mscorlib.dll)
  System.Collections (in System.Collections.dll)

public void ForEach(
	Action<T> action
)

Parameters

action
Type: System.Action<T>

The Action<T> delegate to perform on each element of the List<T>.

ExceptionCondition
ArgumentNullException

action is null.

The Action<T> is a delegate to a method that performs an action on the object passed to it. The elements of the current List<T> are individually passed to the Action<T> delegate.

This method is an O(n) operation, where n is Count.

Modifying the underlying collection in the body of the Action<T> delegate is not supported and causes undefined behavior.

The following example demonstrates the use of the Action<T> delegate to print the contents of a List<T> object. In this example the Print method is used to display the contents of the list to the console.

NoteNote

In addition to displaying the contents using the Print method, the C# example demonstrates the use of anonymous methods to display the results to the console.

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<String> names = new List<String>();
        names.Add("Bruce");
        names.Add("Alfred");
        names.Add("Tim");
        names.Add("Richard");

        // Display the contents of the list using the Print method.
        names.ForEach(Print);

        // The following demonstrates the anonymous method feature of C# 
        // to display the contents of the list to the console.
        names.ForEach(delegate(String name)
        {
            Console.WriteLine(name);
        });
    }

    private static void Print(string s)
    {
        Console.WriteLine(s);
    }
}
/* This code will produce output similar to the following:
 * Bruce
 * Alfred
 * Tim
 * Richard
 * Bruce
 * Alfred
 * Tim
 * Richard
 */

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
Show:
© 2015 Microsoft