正则表达式

JAVA正则表达式语法示例与语法大全

电话号码转换

public static void main(String[] args) {
        //原始电话号码
        String phoneNumber = "+1(111)222-3333";
        String phone = "";
        for (int i = 1; i < phoneNumber.length(); i++) {
            int ch = phoneNumber.charAt(i);
            if (ch >= '0' && ch <= '9') {
                phone += (char) ch;
            }
        }
        System.out.println(phone);
        //使用正则
        String phone2 = phoneNumber.replaceAll("\\D", "");
        System.out.println(phone2);
}

去除标点符号

参考

public static void main(String[] args) {
    String text = "+1(111)222-3333,23d:'asd-=*&sad123";
    //"\\p{P}"表示匹配所有的Unicode标点符号， "\\s"表示匹配所有空白字符
    String newText = text.replaceAll("\\p{P}", " ").replaceAll("\\s", " ");
    System.out.println(newText);
}

反向引用

public class Main {
    public static void main(String[] args) {
        String s = "the quick brown fox jumps over the lazy dog.";
        String r = s.replaceAll("\\s([a-z]{4})\\s", " <b>$1</b> ");
        System.out.println(r);
    }
}