Jquery: filter input on keypress

Question

I have a text field, which will accept only the following characters:

Allowed characters: [a-z 0-9 + # - .]

This is the same filter SO

Answer 1

/[^A-Za-z0-9+#-\.]/

This negates the match of any one of those characters. To make it match more than one character, you have to use a + in there:

/[^A-Za-z0-9+#-\.]+/
                  ^

And now to match the whole string, you need to add anchors:

/^[^A-Za-z0-9+#-\.]+$/
 ^                  ^

EDIT: Okay, it seems that the - here is also creating a range from character # to .. In this case, you can either escape it, or put it at the end:

/^[^A-Za-z0-9+#\-\.]+$/

/^[^A-Za-z0-9+#\.-]+$/