Question

What regular expression using java could be used to filter out dashes ‘-‘ and open close round brackets from a string representing phone numbers…

so that [phone] should give 2348879999
and similarly 234-887-9999 should give 2348879999.

Thanks,

Answer 1

phoneNumber.replaceAll("[\\s\\-()]", "");

The regular expression defines a character class consisting of any whitespace character (\s, which is escaped as \\s because we’re passing in a String), a dash (escaped because a dash means something special in the context of character classes), and parentheses.

See String.replaceAll(String, String).

EDIT

Per gunslinger47:

phoneNumber.replaceAll("\\D", "");

Replaces any non-digit with an empty string.