打印僅在匹配中第一次出現

Question

我用下面的代碼來提取用戶的年齡在一份文件中，但他的年齡出現了幾次：

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)); 
       } 

最後我得到的結果是：

55 
55 
55 

如何才能打印55一次？

在此先感謝。

Answer 1

您可以通過添加使其非貪婪？

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

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