c# get substring of enum value

Question

Is there a clever way to get an enum value by comparing a substring a la String.Contains with the enum? I checked this implementation (Convert a string to an enum in C#), but would like to have an intelligent extension doing the same but including substrings comparison, something like TryParse with an option to check the whole substring of the enum values.

    public static void Main()
{
    string a = "HANS";
    GetName(a); // prints Hans
    
    string a1 = "Peter";
    GetName(a1); // should print enum value "WolfgangPeterDietrich " containing the substring "Peter"
}

public enum MyNames
{
    Hans = 0,
    WolfgangPeterDietrich = 3,
}

public static void GetName(string a)
{
    MyNames dif;
    // this works fine, ignore case
    if (Enum.TryParse(a, true, out dif))
    {      
        System.Console.WriteLine(dif.ToString());
    }
    // ToDo: check for substring ??
}

`Enum.GetNames().Where(n => c.Contains(a, StringComparison.OrdinalIgnoreCase))` might be a start? — stuartd, Oct 06 '21 at 11:50
Also, if it don't find, what it should print? Is it case sensitive or insensitive? — Magnetron, Oct 06 '21 at 11:52
First occurence should be fine, and if it dont find, just do nothing is fine — KevinNivek, Oct 06 '21 at 11:59

score 1 · Answer 1 · answered Oct 06 '21 at 11:55

1

This approach takes the first occurrence found, and is case insensitive.

public static void GetName(string a)
{
    string? result = Enum.GetNames<MyNames>()
        .FirstOrDefault(x => x.Contains(a, StringComparison.OrdinalIgnoreCase));
    System.Console.WriteLine(result);
}

answered Oct 06 '21 at 11:55

Magnetron

7,495
1
25
41

that does exactly the job, thanks a lot for your help! – KevinNivek Oct 06 '21 at 12:00
just changed to ```Enum.GetNames(typeof(MyNames)).FirstOrDefault``` – KevinNivek Oct 06 '21 at 12:15

score 0 · Answer 2 · answered Oct 06 '21 at 12:02

0

Just a prototype to fix with boundary cases and assertions:

public static T EnumNameContains<T>(string substringOfName) where T: struct
{
    return (T)Enum.Parse(typeof(T), 
        Enum.GetNames(typeof(T)).FirstOrDefault(
            name => name.IndexOf(substringOfName,StringComparison.CurrentCultureIgnoreCase) >= 0));
}

I guess can help.

answered Oct 06 '21 at 12:02

GibbOne

629
6
10

1

nice one following https://stackoverflow.com/questions/28279933/performance-of-indexofchar-vs-containsstring-for-checking-the-presence-of-a – KevinNivek Oct 06 '21 at 12:23

score 0 · Answer 3 · answered Oct 06 '21 at 12:03

You can try this

public static void GetName(string a)
        {
            MyNames dif;
            // this works fine, ignore case
            if (Enum.TryParse(a, true, out dif))
            {
                System.Console.WriteLine(dif.ToString());
            }
            else
            {
                var result = Enum.GetNames(typeof(MyNames)).Where(dd => dd.Contains(a, StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
                System.Console.WriteLine(result);
            }
            
        }

c# get substring of enum value

3 Answers3