3 different ways to loop through a C# List

List<T> are one of the most used data structure in C# language.

Iterating over the List<T> and performing some operations on list elements are, quite common in our daily projects.

To loop through a list in C# we can use 3 different ways.

1. Using C# foreach statement.
2. Using C# List.ForEach method.
3. Using simple for loop.

Let’s go through an example to understand it further.

First we will create a simple C# list.

List<string> languages = new List<string>() { "C#","Asp.Net","DotNet Core"};

Now we will see different ways to loop a C# List.

Using C# foreach statement #

Using foreach statement to loop a C# list is widely used method.

And further we can perform any operation on the list elements.

In the below example I have created a list of strings.

Then looping that list using foreach and further printing the list elements on the console.

///Method to Loop C# list
void loopList()
{
   List<string> languages = new List<string>() { "C#","Asp.Net","DotNet Core"};
   
   foreach (string lang in languages)
   {
        Console.WriteLine(lang);
   }
}

Now we will create a list of objects and loop them using foreach statement.

Defined a Person class and created a list with two person elements.

List<Person> persons = new List<Person>() 
{ 
      new Person() { Id = 1, Name="Arun" },
      new Person() { Id = 2, Name="Kumar"} 
};

Now we can use foreach statement to loop through list of objects.

void loopListOfObjects(List<Persons> persons){
 foreach(var person in persons)
    {
        Console.WriteLine(person.Name);            
        Console.WriteLine(person.Id);
    }
}

Using C# List.ForEach method #

List<T>.ForEach method performs the given action on each element of the List.

It accepts Action<T> delegate parameter.

The following example loop through the list of objects using Action<T> delegate.

persons.ForEach((person) =>
    {
        Console.WriteLine(person.Name);
        Console.WriteLine(person.Id);
    });

Using for statement #

We can use legacy for statement to loop through a C# list, if you want to perform any action on the list elements based on the index.

Otherwise stick with foreach or List<T>.ForEach() methods.

for(var i=0;i<persons.Count;i++)
    {
        Console.WriteLine(persons[i].Name);
        Console.WriteLine(persons[i].Id);
    }

Summary #

In this tutorial we learnt, how to loop through a list in C# using foreach, List<T.ForEach and for statement.