Combine StringComparison enums

Question

I was about to write a method that has to decide whether or not to ignore case while comparing two strings.

public bool IsCaseSensitiveUsing(StringComparison comparer)
{
    if (comparer == StringComparison.CurrentCulture | 
        comparer == StringComparison.InvariantCulture | 
        comparer == StringComparison.Ordinal))
            return true;

    return false;

 }

Is there a better way to do it?

The method will not reflect the real parameter. `OrdinalIgnoreCase` is the same as `CurrentCultureIgnoreCase` and `InvariantCulture.IgnoreCase` ? — Mhd, Jul 01 '17 at 20:41
Define "better"? You can do `return (int)comparer % 2 != 0` or `return !comparer.ToString().EndsWith("IgnoreCase")`, It's shorter, but I wouldn't call that better — Kevin Gosse, Jul 01 '17 at 20:43
@KevinGosse "better" means shorter. I like `(int)comparer % 2 != 0` idea. But why is not better? — Mhd, Jul 01 '17 at 20:48
Side note: StringComparison.CurrentCulture is not "case sensitive" or "case insensitive" - so you code is not exactly correct... Whether you care or not is different question - it does not impact answers of "how to check if enum value belongs to as set" like - https://stackoverflow.com/questions/7477692/c-best-way-to-check-against-a-set-of-enum-values — Alexei Levenkov, Jul 01 '17 at 21:46

score 0 · Answer 1 · answered Jul 01 '17 at 20:36

I suggest implementng extension method:

   public static class StringComparisonExtensions {
     public static bool IsCaseSensitiveUsing(this StringComparison value) {
       return (value == StringComparison.CurrentCulture || 
               value == StringComparison.InvariantCulture || 
               value == StringComparison.Ordinal); 
     }
   } 

   ....

   StringComparison myComparison = ...

   // Check as if StringComparison has IsCaseSensitiveUsing method:
   if (myComparison.IsCaseSensitiveUsing()) {
     ...
   }

score 0 · Answer 2 · answered Jul 01 '17 at 20:40

You can make a set of StringComparison values that require case sensitivity, and use it in your method:

private static readonly ISet<StringComparison> caseSensitive = new HashSet<StringComparison> {
    StringComparison.CurrentCulture
,   StringComparison.InvariantCulture
,   StringComparison.Ordinal
};
public static bool IsCaseSensitiveUsing(StringComparison comparer) {
    return caseSensitive.Contains(comparer);
}

Combine StringComparison enums

2 Answers2