How can I split a Unicode string into multiple Unicode characters in C#?

Question

If I have a string like "😀123👨‍👩‍👧‍👦", how can I split it into an array, which would look like ["😀", "1", "2", "3", "👨‍👩‍👧‍👦"]? If I use ToCharArray() the first Emoji is split into 2 characters and the second into 7 characters.

Update

The solution now looks like this:

public static List<string> GetCharacters(string text)
{
    char[] ca = text.ToCharArray();
    List<string> characters = new List<string>();
    for (int i = 0; i < ca.Length; i++)
    {
        char c = ca[i];
        if (c > ‭65535‬) continue;
        if (char.IsHighSurrogate(c))
        {
            i++;
            characters.Add(new string(new[] { c, ca[i] }));
        }
        else
            characters.Add(new string(new[] { c }));
    }
    return characters;
}

Please note that, as mentioned in the comments, it doesn't work for the family emoji. It only works for emojis that have 2 characters or less. The output of the example would be: ["😀", "1", "2", "3", "👨‍", "👩‍", "👧‍", "👦"]

Answer 1

.NET represents strings as a sequence of UTF-16 elements. Unicode code points outside the Base Multilingual Plane (BMP) will be split into a high and low surrogate. The lower 10 bits of each forms half of the real code point value.

There are helpers to detect these surrogates (eg. Char.IsLowSurrogate).

You need to handle this yourself.