c# - Error in declaring default parameters for method -

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• optional parameters “must compile-time constant” 8 answers

i using default parameters i'm getting error

default parameter value 'regularexpression' must compile time constant

here method signature:

public static pipe.datatypes.buyflow.entities.question getemailaddressquestion(string regularexpression = regularexpressions.emailaddressregex, int rank = 1, bool isrequired = true) { } 

and here property:

public static string emailaddressregex {     {             string emailaddressregex = @"^[a-za-z0-9\._%\+\-]+@([a-za-z0-9\-]{1,40}\.)+([a-za-z0-9]{2,4}|museum)$";             return emailaddressregex;         } } 

it error message says. default parameters have constants (at compile time).

the getter of emailaddressregex return different values during runtime. same value not known compiler.

so change emailaddressregex const string compiler error gone.

e.g.

public const string emailaddressregex = @"^[a-za-z0-9\._%\+\-]+@([a-za-z0-9\-]{1,40}\.)+([a-za-z0-9]{2,4}|museum)$";