.ToInt extension method

Program.cs

using System;
using System.Linq;
using System.Collections.Generic;
using static Sugar;

class Program
{
    static void Main(string[] args)
    {
        if ("1111".ToInt() is int parsed)
        {
            Console.WriteLine(parsed);
        }

        int result = "2222".ToInt() ?? 0;
        Console.WriteLine(result);

        var maybeNumbers = List("AAA", "111", "NOPE", "333", "YOOOOO", "012311");
        maybeNumbers.Select(s => s.ToInt())
                    .Compact()
                    .ForEach(f => Console.WriteLine(f));
    }
}

public static class Sugar
{
    public static int? ToInt(this string n)
    {
        int result = 0;
        if (int.TryParse(n, out result)) return result;
        else return null;
    }

    public static IEnumerable<T> Compact<T>(this IEnumerable<T> os)
    {
        return os.Where(os => os is not null);
    }

    public static void ForEach<T>(this IEnumerable<T> os, Action<T> action)
    {
        foreach(var o in os) action(o);
    }

    public static List<T> List<T>(T item, params T[] rest)
    {
        var list = new List<T> { item };
        list.AddRange(rest);
        return list;
    }
}