c# - Best way of mapping external error codes to internal codes -

what mean if error code 300 service, , need map our own internal error code (say 450), whats best way of doing this.

current system uses constants keep track of internal errors:

public const string error_some = "450"; public const string error_another = "460";... 

so thinking of having set of constants external errors , have function mapping two:

public const string ext_error_some = "300"; public const string ext_error_another = "800"; ... public string maperror(string externalerror) {     if(externalerror == ext_error_some) // can switch statement          return error_some;     else if (externalerror == ext_error_another)          return error_another;     ... } 

the question is: "is there better way"?

you can use dictionary<string, string>:

private readonly var errormap = new dictionary<string, string>() {     {ext_error_some, error_some},     ⋮ };  public string maperror(string externalerror) {     return errormap[externalerror]; }