How can I convert an int32 array to a list of integers in C#?

Converting an int32 array to a List in C# is a common task. Here's how you can accomplish this with a few different methods, along with explanations:

1. Using the `ToList()` Method (LINQ):

The most straightforward method is using LINQ's `ToList()` extension method. This is concise and easy to read. Make sure you have `using System.Linq;` at the top of your file.

using System;
using System.Collections.Generic;
using System.Linq;

public class Example
{
  public static void Main(string[] args)
  {
    int[] intArray = { 1, 2, 3, 4, 5 };
    List<int> intList = intArray.ToList();

    foreach (int number in intList)
    {
      Console.WriteLine(number); // Output: 1 2 3 4 5
    }
  }
}

- This method creates a new List<int> from the array by iterating through each element and adding it to the list. It is generally efficient for most use cases.

2. Using a `foreach` Loop:

You can manually create a List<int> and populate it by iterating over the array with a foreach loop.

using System;
using System.Collections.Generic;

public class Example
{
  public static void Main(string[] args)
  {
    int[] intArray = { 1, 2, 3, 4, 5 };
    List<int> intList = new List<int>();

    foreach (int number in intArray)
    {
      intList.Add(number);
    }

    foreach (int number in intList)
    {
      Console.WriteLine(number); // Output: 1 2 3 4 5
    }
  }
}

- This method is more verbose than using ToList(), but it provides more control over the process if needed.

3. Using `List` Constructor with Array:

You can use the List<int> constructor that takes an IEnumerable<int>, which an array implements. This is functionally equivalent to the ToList() method but is less commonly used.

using System;
using System.Collections.Generic;

public class Example
{
  public static void Main(string[] args)
  {
    int[] intArray = { 1, 2, 3, 4, 5 };
    List<int> intList = new List<int>(intArray);

    foreach (int number in intList)
    {
      Console.WriteLine(number); // Output: 1 2 3 4 5
    }
  }
}

- This method efficiently initializes the list with the elements from the given array.

Recommendation:

For most situations, the `ToList()` method (using LINQ) is the most recommended approach due to its simplicity and readability. It is also generally efficient. The other methods are valid but are typically used when you require more control or are in a context where LINQ is not preferable.

In summary, all three methods achieve the same result of converting an int32 array to a List<int>, but the LINQ ToList() method is usually the most convenient option.

Learn more about this