public static boolean isInternationalPhoneNumber ( String s ) { if ( isEmpty ( s ) ) return defaultEmptyOK ; String normalizedPhone = stripCharsInBag ( s , phoneNumberDelimiters ) ; return isPositiveInteger ( normalizedPhone ) ; }
isInternationalPhoneNumber returns true if string s is a valid international phone number . Must be digits only ; any length OK . May be prefixed by + character .