Is there a C case insensitive equals operator

Question

I know that the following is case sensitive   if  StringA    StringB      So is there an operator which will compare two strings in an insensitive manner

User · Answer

The best way to compare 2 strings ignoring the case of the letters is to use the String Equals static method specifying an ordinal ignore case string comparison  This is also the fastest way  much faster than converting the strings to lower or upper case and comparing them after that   I tested the performance of both approaches and the ordinal ignore case string comparison was more than 9 times faster  It is also more reliable than converting strings to lower or upper case  check out the Turkish i problem   So always use the String Equals method to compare strings for equality   String Equals string1  string2  StringComparison OrdinalIgnoreCase     If you want to perform a culture specific string comparison you can use the following code   String Equals string1  string2  StringComparison CurrentCultureIgnoreCase     Please note that the second example uses the the string comparison logic of the current culture  which makes it slower than the  ordinal ignore case  comparison in the first example  so if you don t need any culture specific string comparison logic and you are after maximum performance  use the  ordinal ignore case  comparison   For more information  read the full story on my blog

User · Answer

Others answer are totally valid here  but somehow it takes some time to type StringComparison OrdinalIgnoreCase and also using String Compare   I ve coded simple String extension method  where you could specify if comparison is case sensitive or case senseless with boolean - see following answer   https   stackoverflow com a 49208128 2338477

User · Answer

or  if  StringA Equals StringB  StringComparison CurrentCultureIgnoreCase       but you need to be sure that StringA is not null  So probably better tu use   string Equals StringA   StringB  StringComparison CurrentCultureIgnoreCase     as John suggested  EDIT  corrected the bug

User · Answer

Here an idea to simplify the syntax   public class IgnoreCase       private readonly string  value       public IgnoreCase string s                 value   s             protected bool Equals IgnoreCase other                return this    other             public override bool Equals object obj                return obj    null  amp  amp                  ReferenceEquals this  obj      obj GetType      GetType    amp  amp  this     IgnoreCase  obj               public override int GetHashCode                 return  value  GetHashCode      0             public static bool operator    IgnoreCase a  IgnoreCase b                return string Equals a  b  StringComparison OrdinalIgnoreCase              public static bool operator    IgnoreCase a  IgnoreCase b                return   a    b              public static implicit operator string IgnoreCase s                return s  value             public static implicit operator IgnoreCase string s                return new IgnoreCase s             Usable like   Console WriteLine  IgnoreCase   a      b       false Console WriteLine  IgnoreCase   abc      abC       true Console WriteLine  IgnoreCase   Abc      aBc       true Console WriteLine  IgnoreCase   ABC      ABC       true

User · Answer

string Compare string1  string2  true

User · Answer

if  StringA ToUpperInvariant      StringB ToUpperInvariant        People report ToUpperInvariant   is faster than ToLowerInvariant

User · Answer

I am so used to typing at the end of these comparison methods    StringComparison   So I made an extension   namespace System     public static class StringExtension               public static bool Equals this string thisString  string compareString               StringComparison stringComparison                        return string Equals thisString  compareString  stringComparison                       Just note that you will need to check for null on thisString prior to calling the ext

User · Answer

Try this   string Equals a  b  StringComparison CurrentCultureIgnoreCase

User · Answer

There are a number of properties on the StringComparer static class that return comparers for any type of case-sensitivity you might want   StringComparer Properties  For instance  you can call  StringComparer CurrentCultureIgnoreCase Equals string1  string2    or  StringComparer CurrentCultureIgnoreCase Compare string1  string2    It s a bit cleaner than the string Equals or string Compare overloads that take a StringComparison argument

User · Answer

string Equals StringA  StringB  StringComparison CurrentCultureIgnoreCase

User · Answer

System Collections CaseInsensitiveComparer   or  System StringComparer OrdinalIgnoreCase

User · Answer

You can use   if  stringA equals StringB  StringComparison CurrentCultureIgnoreCase

User · Answer

Operator  NO  but I think you can change your culture so that string comparison is not case-sensitive      you ll want to change this    System Threading Thread CurrentThread CurrentCulture    and you ll want to custimize this System Globalization CultureInfo CompareInfo   I m confident that it will change the way that strings are being compared by the equals operator

[c#] Is there a C# case insensitive equals operator?

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