Print regex matches in java

Question

So I have an IP address as a string. I have this regex (\\d{1-3})\\.(\\d{1-3})\\.(\\d{1-3})\\.(\\d{1-3}) How do I print the matching groups?

Thanks!

Answer 1

If you use Pattern and Matcher to do your regex, then you can ask the Matcher for each group using the group(int group) method

So:

Pattern p = Pattern.compile("(\\d{1-3}).(\\d{1-3}).(\\d{1-3}).(\\d{1-3})"); 
Matcher m = p.matcher("127.0.0.1"); 
if (m.matches()) {   
  System.out.print(m.group(1));  
  // m.group(0) is the entire matched item, not the first group.
  // etc... 
}