C# 11 list pattern

readme.md

About

Imagine a developer needs to read data were each line of a list or a list of list needs to validate that the first element and last element must be specific values.

In this case, first element a 1 and the last a 4.

Data

[1, 4]
[1, 2, 3]
[1, 2, 3, 4]
[0, 2, 3, 4]
[1, 2, 3, 5, 4]

Results

0  is match    Not a match
1  is match    Not a match
2  is match    Match
3  is match    Not a match
4  is match    Match

See List patterns docs.

Demo.cs

using System.Text.Json;

namespace TODO;

class Samples
{
    public static void IntegerListMatch()
    {

        List<List<int>> list =
        [
            [1, 4],
            [1, 2, 3],
            [1, 2, 3, 4],
            [0, 2, 3, 4],
            [1, 2, 3, 5 ,4],
        ];

        Console.WriteLine("Data");

        foreach (var sublist in list)
        {
            Console.WriteLine($"[{string.Join(", ", sublist)}]");
        }

        Console.WriteLine();

        foreach (var (index, item) in list.Index())
        {
            Console.WriteLine($"{index,-2} is match    {(item is [1, 2, 3, .., 4] ? "Match" : "Not a match")}");
        }

    }

}