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

The following will match on any string that starts with mailto, ftp or http:

 RegEx reg = new RegEx("^(mailto|ftp|http)");

To break it down:

• ^ matches start of line
• (mailto|ftp|http) matches any of the items separated by a |

I would find StartsWith to be more readable in this case.