How to remove an item from a C# List

I’ve already written about how to add or insert an item to a C# List, but what about if you want to remove an item from a C# List? In this post I’ll provide examples showing how to remove a string from a list, remove an integer from a list, and how to remove a custom object from a C# List.

If we start with a list of strings, in this case sports :

List<string> sports = new List<string> {"Tennis", "Baseball", "Swimming", "Skiing", "Running", "Karate"};

We want to remove Skiing from the list, and would do so by using the Remove method on the list, by providing the item as a property, in this case a string. If a match for the item is found, it will be removed:

sports.Remove("Skiing");

So if we were dealing with a list of integers :

List<int> tickets = new List<int> { 54, 12, 3, 41, 15, 16, 702, 89, 109 };

… we’d remove an item like this, again specifying the item that needs to be removed, in this case an integer:

tickets.Remove(12);

It’s more than likely that in a real application you’ll be dealing with a list of custom objects, so next I’ll explain how to remove custom objects from a list.

Remove a custom object from a C# List

I’ll start again with the list of drinks similar to my previous post, and will then remove an item using it’s known index (position) in the List, using RemoveAt:

List<Drink> drinks = new List<Drink> {
  new Drink{ Name = "Sambucca", Id=9 },
  new Drink{ Name = "Prosecco", Id=192 },
  new Drink{ Name = "Vodka and orange", Id=17 },
  new Drink{ Name = "Martini", Id=43 },
  new Drink{ Name = "Apple Juice", Id=149 },
  new Drink{ Name = "Mojito", Id=44 },
  new Drink{ Name = "Pale Ale", Id=18 } };

WriteList(drinks, "Drinks");
Console.WriteLine("Now remove the Apple Juice from the list of drinks using it's index:");
drinks.RemoveAt(4);
WriteList(drinks, "Amended drinks list");

If you run this code, you’ll see something like this:

However, to remove an item from the List by it’s value, the object class, in this case Drink, needs a new method added, as follows:

//add to Drink class
public bool Equals(Drink other)
{
  return Name.Equals(other.Name);
}

Let’s say we have added a drink to the list :

Drink coke = new Drink { Name = "Coke", Id = 55 };
drinks.Add(coke);

… and then to remove the drink from the list simply involves doing this:

drinks.Remove(coke);

Summary

I’ve explained how to remove a string from a list of strings, an integer from a list of integers, and how to remove a custom object from a list in C#.