Transform title into dashed URL-friendly string [closed]

Answer 1

Most "sluggifiers" (methods for converting to friendly-url type names) tend to do the following:

1. Strip everything except whitespace, dashes, underscores, and alphanumerics.
2. (Optional) Remove "common words" (the, a, an, of, et cetera).
3. Replace spaces and underscores with dashes.
4. (Optional) Convert to lowercase.

As far as I know, StackOverflow's sluggifier does #1, #3, and #4, but not #2.