package com.wy.regular;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegularTest {

	public static void main(String[] args) {
		/*
		 * back refenrences 向前引用
		 * \\1 指的是第二個組的結果和第一個組的需要一樣
		 * (\\d(\\d))\\2的結果是false
		 */
		Pattern pattern = Pattern.compile("(\\d(\\d))\\2");
		String str = "1212";
		Matcher matcher = pattern.matcher(str);
		pri(matcher.matches());//true
	}

	private static void pri(boolean str) {
		System.out.println(str);
	}
}