How to Iterate Over List in C#: Simple Syntax and Examples

In C#, you can iterate over a list using a foreach loop to access each item easily or a for loop to use indexes. The foreach loop is simple and safe for reading items, while the for loop gives more control when you need the index.

Syntax

There are two common ways to iterate over a list in C#:

• foreach loop: Automatically goes through each item in the list.
• for loop: Uses an index to access each item by position.

Use foreach when you only need to read items. Use for when you need the index or want to modify items.

csharp

List<string> items = new List<string> { "apple", "banana", "cherry" };

// foreach loop
foreach (string item in items)
{
    Console.WriteLine(item);
}

// for loop
for (int i = 0; i < items.Count; i++)
{
    Console.WriteLine(items[i]);
}

Example

This example shows how to print all items in a list using both foreach and for loops.

csharp

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        List<string> fruits = new List<string> { "apple", "banana", "cherry" };

        Console.WriteLine("Using foreach loop:");
        foreach (string fruit in fruits)
        {
            Console.WriteLine(fruit);
        }

        Console.WriteLine("Using for loop:");
        for (int i = 0; i < fruits.Count; i++)
        {
            Console.WriteLine(fruits[i]);
        }
    }
}

Output

Using foreach loop:
apple
banana
cherry
Using for loop:
apple
banana
cherry

Common Pitfalls

Common mistakes when iterating over lists include:

• Modifying the list inside a foreach loop, which causes errors.
• Using wrong loop conditions in for loops, like i <= list.Count instead of i < list.Count, causing out-of-range errors.
• Confusing the item variable with the index in foreach loops (there is no index).

Always use for if you need to modify the list or access indexes.

csharp

List<int> numbers = new List<int> {1, 2, 3};

// Wrong: modifying list inside foreach (throws error)
// foreach (int n in numbers)
// {
//     numbers.Remove(n);
// }

// Right: use for loop to modify safely
for (int i = numbers.Count - 1; i >= 0; i--)
{
    numbers.RemoveAt(i);
}

Quick Reference

Here is a quick summary of how to iterate over a list in C#:

Method	Usage	When to Use
foreach	for each item in list	Reading items, simple iteration
for	for (int i = 0; i < list.Count; i++)	When index needed or modifying list
List.ForEach(Action)	list.ForEach(item => ...)	Quick action on each item (read-only)

Key Takeaways

Use foreach loop for simple, safe iteration over list items.

Use for loop when you need the index or want to modify the list.

Never modify a list inside a foreach loop to avoid runtime errors.

Always check loop conditions carefully to prevent out-of-range errors.

List.ForEach method is a concise alternative for read-only actions on items.