// 電話號碼匹配
// 手機號段只有 13xxx 15xxx 18xxxx 17xxx
System.out.println("18304072984".matches("1[3578]\\d{9}")); // true

// 座機號：010-65784236,0316-3312617,022-12465647,03123312336
String regex = "0\\d{2}-?\\d{8}|0\\d{3}-?\\d{7}";
String telStr = "010-43367458";
System.out.println(telStr.matches(regex)); // true

String mail = "i@jiaobuchong.com.cn";
String reg = "[a-zA-Z_0-9]+@[a-zA-Z0-9]+(\\.[a-zA-Z]+){1,2}";
System.out.println(mail.matches(reg)); // true

String input = "神探狄仁&*%$杰之四大天王@bdfbdbdfdgds23532";
String reg = "[^\\u4e00-\\u9fa5]";
input = input.replaceAll(reg, "");
System.out.println(input); // 神探狄仁杰之四大天王

1. ((A)(B(C)))
2. (A)
3. (B(C))
4. (C)

// 這個正則表達式有兩個組，
// group(0) 是 \\$\\{([^{}]+?)\\}
// group(1) 是 ([^{}]+?)
String regex = "\\$\\{([^{}]+?)\\}";
Pattern pattern = Pattern.compile(regex);
String input = "${name}-babalala-${age}-${address}";

Matcher matcher = pattern.matcher(input);
System.out.println(matcher.groupCount());
// find() 像迭代器那樣向前遍歷輸入字符串
while (matcher.find()) {
 System.out.println(matcher.group(0) + ", pos: "
 + matcher.start() + "-" + (matcher.end() - 1));
 System.out.println(matcher.group(1) + ", pos: " +
 matcher.start(1) + "-" + (matcher.end(1) - 1));
}

String regex = "(\\$\\{([^{}]+?)\\})";
Pattern pattern = Pattern.compile(regex);
String input = "${name}-babalala-${age}-${address}";

Matcher matcher = pattern.matcher(input);
// matcher.find() 方法會對 input 這個字符串多次進行匹配，如果能匹配到，這個匹配結果里就會包含多個分組，我們可以從分組里提取我們想要的結果
while (matcher.find()) {
 System.out.println(matcher.group(0) + ", pos: " + matcher.start());
 System.out.println(matcher.group(1) + ", pos: " + matcher.start(1));
 System.out.println(matcher.group(2) + ", pos: " + matcher.start(2));
}

 // 這個正則表達式會提取字符串中的「數(shù)字」和「字母」
 Pattern pattern = Pattern.compile("([0-9]+).*?([a-zA-Z]+)");
 String input = "那就20200719這樣吧sunny。。。。。。。122432該拿什么與眼淚抗衡twinkle";
 Matcher matcher = pattern.matcher(input);
 // 每個匹配到的子串分組的個數(shù)
 int group = matcher.groupCount();
 // 如果輸入串有多個可被匹配的子串，這里會多次進行匹配
 while (matcher.find()) {
 System.out.println("匹配到的子串：" + matcher.group()); // 匹配到的子串
 for (int i = 1; i <= group; i++) {
 System.out.println("分組" + i + ": " + matcher.group(i));
 }
 }

String tel = "18304072984";
// 括號表示組，被替換的部分$n表示第n組的內容
tel = tel.replaceAll("(\\d{3})\\d{4}(\\d{4})", "$1****$2");
System.out.print(tel); // output: 183****2984

String one = "hello girl hi hot".replaceFirst("(\\w+)\\s+(\\w+)", "$2 $1"); 
String two = "hello girl hi hot".replaceAll("(\\w+)\\s+(\\w+)", "$2 $1"); 
System.out.println(one); // girl hello hi hot
System.out.println(two); // girl hello hot hi

String input = "假如生活欺騙了你，，，相信吧，，，快樂的日子將會來臨?。?！…………";

// 重復標點符號替換
String duplicateSymbolReg = "([。？！?!，]|\\.\\.\\.|……)+";
input = input.replaceAll(duplicateSymbolReg, "$1");
System.out.println(input);

String ip = "192.68.1.254 102.49.23.013 10.10.10.10 2.2.2.2 8.109.90.30";
ip = ip.replaceAll("(\\d+)", "00$1");
System.out.println(ip);

ip = ip.replaceAll("0*(\\d{3})", "$1");
System.out.println(ip);
String[] strs = ip.split(" ");

Arrays.sort(strs);
for (String str : strs) {
 str = str.replaceAll("0*(\\d+)", "$1");
 System.out.println(str);
}

/* 這個正則表達式表示 安安靜靜 這樣的疊詞 */
String regex = "(.)\\1(.)\\2"; 
System.out.println("安安靜靜".matches(regex)); // true
System.out.println("安靜安靜".matches(regex)); // false

String regex = "(..)\\1"; 
System.out.println("安靜安靜".matches(regex)); // true
System.out.println("安安靜靜".matches(regex)); // false

String str = "我我...我我...我要..要要...要要...找找找一個....女女女女...朋朋朋朋朋朋...友友友友友..友.友...友...友友?。?！";
 
/*將 . 去掉*/
str = str.replaceAll("\\.+", "");
System.out.println(str);

str = str.replaceAll("(.)\\1+", "$1");
System.out.println(str);

"xx12abdd12345".replaceAll("(\\d{2}).+?\\1", ""); //結果為 xx345