Print only the first occurrence in a matcher

Question

I use the following code to extract the age of a user in one document, but his age appears several times:

Pattern r = Pattern.compile("(\\d{2})(?=-year-old)");
Matcher matcher = r.matcher("He is a 55-year-old doctor. xxxxx. As a 55-year-old man he xxxx. When he is 55-year-old , xxxx");
if(matcher.find()) {    
                System.out.println(matcher.group(0));
                }

Finally I get the result:

55
55
55

How can I just print 55 once?

Thanks in advance.

Your code as it is prints `55` only once. Is that not what you want?? — Codebender, Jun 19 '15 at 03:41
I should mention that "xxx" in the text also contains other numbers. — Steven Luo, Jun 19 '15 at 05:30

score -1 · Accepted Answer · edited May 23 '17 at 12:22

-1

You can make it non-greedy by adding ?

Pattern r = Pattern.compile("(\\d{2})(?=-year-old)?");

should work, click for detail

edited May 23 '17 at 12:22

Community

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answered Jun 19 '15 at 03:52

TheCodingFrog

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`"(\\d{2})(?=-year-old)?"` means there is no use in the lookahead, and you suggest `\d{2}`. However, OP code works anyway. – Wiktor Stribiżew Apr 26 '20 at 09:45

Print only the first occurrence in a matcher

1 Answers1