我試圖用一個簡單的正則表達式匹配patttern但得到一些意想不到的結果......正則表達式的「貪婪」檢查
的搜索模式和結果如下,
public class Test {
public static void main(String[] args) throws IOException {
Pattern p = Pattern.compile(".*xx");
Matcher m = p.matcher("yyxxxyxx");
while (m.find()){
System.out.println("match start");
System.out.println("Start = " + m.start());
System.out.println("End = " + m.end());
System.out.println("Group = " + m.group());
}
}
}
結果:
match start
Start = 0
End = 8
Group = yyxxxyxx
預期結果:
match start
Start = 0
End = 4
Group = yyxx
match start
Start = 4
End = 8
Group = xyxx
有人可以解釋正則表達式的運作方式嗎?