This topic has not yet been rated - Rate this topic

List<T>.Remove Method

Silverlight

Removes the first occurrence of a specific object from the List<T>.

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

public bool Remove(
	T item
)

Parameters

item: Type: T
The object to remove from the List<T>. The value can be null for reference types.

Return Value

Type: System.Boolean
true if item is successfully removed; otherwise, false. This method also returns false if item was not found in the List<T>.

Implements

ICollection<T>.Remove(T)

Remarks

This method determines equality using the default equality comparer EqualityComparer<T>.Default for T, the type of values in the list.

This method performs a linear search; therefore, this method is an O(n) operation, where n is Count.

Examples

The following code example demonstrates Remove method. Several properties and methods of the List<T> generic class are used to add, insert, and search the list. After these operations, the list contains a duplicate. The Remove method is used to remove the first instance of the duplicate item, and the contents are displayed. The Remove method always removes the first instance it encounters.


using System;
using System.Collections.Generic;

public class Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      List<string> dinosaurs = new List<string>();

      outputBlock.Text += String.Format("\nCapacity: {0}", dinosaurs.Capacity) + "\n";

      dinosaurs.Add("Tyrannosaurus");
      dinosaurs.Add("Amargasaurus");
      dinosaurs.Add("Mamenchisaurus");
      dinosaurs.Add("Deinonychus");
      dinosaurs.Add("Compsognathus");

      outputBlock.Text += "\n";
      foreach (string dinosaur in dinosaurs)
      {
         outputBlock.Text += dinosaur + "\n";
      }

      outputBlock.Text += String.Format("\nCapacity: {0}", dinosaurs.Capacity) + "\n";
      outputBlock.Text += String.Format("Count: {0}", dinosaurs.Count) + "\n";

      outputBlock.Text += String.Format("\nContains(\"Deinonychus\"): {0}",
          dinosaurs.Contains("Deinonychus")) + "\n";

      outputBlock.Text += String.Format("\nInsert(2, \"Compsognathus\")") + "\n";
      dinosaurs.Insert(2, "Compsognathus");

      outputBlock.Text += "\n";
      foreach (string dinosaur in dinosaurs)
      {
         outputBlock.Text += dinosaur + "\n";
      }

      outputBlock.Text += String.Format("\ndinosaurs[3]: {0}", dinosaurs[3]) + "\n";

      outputBlock.Text += "\nRemove(\"Compsognathus\")" + "\n";
      dinosaurs.Remove("Compsognathus");

      outputBlock.Text += "\n";
      foreach (string dinosaur in dinosaurs)
      {
         outputBlock.Text += dinosaur + "\n";
      }

      dinosaurs.TrimExcess();
      outputBlock.Text += "\nTrimExcess()" + "\n";
      outputBlock.Text += String.Format("Capacity: {0}", dinosaurs.Capacity) + "\n";
      outputBlock.Text += String.Format("Count: {0}", dinosaurs.Count) + "\n";

      dinosaurs.Clear();
      outputBlock.Text += "\nClear()" + "\n";
      outputBlock.Text += String.Format("Capacity: {0}", dinosaurs.Capacity) + "\n";
      outputBlock.Text += String.Format("Count: {0}", dinosaurs.Count) + "\n";
   }
}

/* This code example produces the following output:

Capacity: 0

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Deinonychus
Compsognathus

Capacity: 8
Count: 5

Contains("Deinonychus"): True

Insert(2, "Compsognathus")

Tyrannosaurus
Amargasaurus
Compsognathus
Mamenchisaurus
Deinonychus
Compsognathus

dinosaurs[3]: Mamenchisaurus

Remove("Compsognathus")

Tyrannosaurus
Amargasaurus
Mamenchisaurus
Deinonychus
Compsognathus

TrimExcess()
Capacity: 5
Count: 5

Clear()
Capacity: 5
Count: 0
 */