How to compare and convert emoji characters in C#

I am trying to figure out how to check if a string contains a specfic emoji. For example, look at the following two emoji:

Bicyclist: http://unicode.org/emoji/charts/full-emoji-list.html#1f6b4

US Flag: http://unicode.org/emoji/charts/full-emoji-list.html#1f1fa_1f1f8

Bicyclist is U+1F6B4, and the US flag is U+1F1FA U+1F1F8.

However, the emoji to check for are provided to me in an array like this, with just the numerical value in strings:

var checkFor = new string[] {"1F6B4","1F1FA-1F1F8"};

How can I convert those array values into actual unicode characters and check to see if a string contains them?

I can get something working for the Bicyclist, but for the US flag I'm stumped.

For the Bicyclist, I'm doing the following:

const string comparisonStr = "..."; //some string containing text and emoji

var hexVal = Convert.ToInt32(checkFor[0], 16);
var strVal = Char.ConvertFromUtf32(hexVal);

//now I can successfully do the following check

var exists = comparisonStr.Contains(strVal);

But this will not work with the US Flag because of the multiple code points.

You already got past the hard part. All you were missing is parsing the value in the array, and combining the 2 unicode characters before performing the check.

Here is a sample program that should work:

static void Main(string[] args)
{
    const string comparisonStr = "bicyclist: \U0001F6B4, and US flag: \U0001F1FA\U0001F1F8"; //some string containing text and emoji
    var checkFor = new string[] { "1F6B4", "1F1FA-1F1F8" };

    foreach (var searchStringInHex in checkFor)
    {
        string searchString = string.Join(string.Empty, searchStringInHex.Split('-')
                                                        .Select(hex => char.ConvertFromUtf32(Convert.ToInt32(hex, 16))));

        if (comparisonStr.Contains(searchString))
        {
            Console.WriteLine($"Found {searchStringInHex}!");
        }
    }
}