You may turn the first .+
lazy, and wrap the later part with a non-capturing optional group:
(.+?)(?:\s\((\d+)\))?$
^ ^^^ ^^
See the regex demo
Actually, if you are using the regex with String#matches()
the last $
is redundant.
Details:
(.+?)
– Group 1 capturing one or zero characters other than a linebreak symbol, as few as possible (thus, allowing the subsequent subpattern to “fall” into a group)(?:\s\((\d+)\))?
– an optional sequence of a whitespace,(
, Group 2 capturing 1+ digits and a)
$
– end of string anchor.
A Java demo:
String[] lst = new String[] {"John Smith","John Smith (123)","John Smith (123) (456)"};
Pattern p = Pattern.compile("(.+?)(?:\\s\\((\\d+)\\))?");
for (String s: lst) {
Matcher m = p.matcher(s);
if (m.matches()) {
System.out.println(m.group(1));
if (m.group(2) != null)
System.out.println(m.group(2));
}
}