Regex pattern for checking if a string starts with a certain substring?

Question

What\'s the regular expression to check if a string starts with \"mailto\" or \"ftp\" or \"joe\" or...

Now I am using C# and code like this in a big if with many ors

Answer 1

I really recommend using the String.StartsWith method over the Regex.IsMatch if you only plan to check the beginning of a string.

• Firstly, the regular expression in C# is a language in a language with does not help understanding and code maintenance. Regular expression is a kind of DSL.
• Secondly, many developers does not understand regular expressions: it is something which is not understandable for many humans.
• Thirdly, the StartsWith method brings you features to enable culture dependant comparison which regular expressions are not aware of.

In your case you should use regular expressions only if you plan implementing more complex string comparison in the future.