Question

Let’s say I need to compare if string x is “A”, “B”, or “C”.

With Python, I can use in operator to check this easily.

if x in ["A","B","C"]:
    do something

With C#, I can do

if (String.Compare(x, "A", StringComparison.OrdinalIgnoreCase) || ...)
    do something

Can it be something more similar to Python?

ADDED

I needed to add System.Linq in order to use case insensitive Contain().

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

class Hello {
    public static void Main() {
        var x = "A";

        var strings = new List<string> {"a", "B", "C"};
        if (strings.Contains(x, StringComparer.OrdinalIgnoreCase)) {
            Console.WriteLine("hello");
        }
    }
}

or

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

static class Hello {
    public static bool In(this string source, params string[] list)
    {
        if (null == source) throw new ArgumentNullException("source");
        return list.Contains(source, StringComparer.OrdinalIgnoreCase);
    }

    public static void Main() {
        string x = "A";

        if (x.In("a", "B", "C")) {
            Console.WriteLine("hello");
        }
    }
}

Answer 1

Use Enumerable.Contains<T> which is an extension method on IEnumerable<T>:

var strings = new List<string> { "A", "B", "C" };
string x = // some string
bool contains = strings.Contains(x, StringComparer.OrdinalIgnoreCase);
if(contains) {
    // do something
}