问题:
在用正则表达式截取字符串时,要先执行m.find(),再输出m.group()。否则会返回"No match found" 异常,为什么?
代码:
public static String truncateSentence(String s,int k) { String regex = "(\\w+\\s{1})"+"{"+ k + "}"; Pattern p = Pattern.compile(regex); Matcher m = p.matcher(s); //throw "No match found" exception if m.find() is not executed. //m.find(); return m.group(); }