List<T>.ForEach Method (Action<T>)
Performs the specified action on each element of the List<T>.
Assembly: mscorlib (in mscorlib.dll)
| Exception | Condition | ||
|---|---|---|---|
| ArgumentNullException | action is null. | ||
| InvalidOperationException | An element in the collection has been modified.
|
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.
Note |
|---|
In addition to displaying the contents using the Print method, the C# example demonstrates the use of 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 */
Available since 10
.NET Framework
Available since 2.0
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0

