Summary of Java Regular expressions

Package Pack;import Java.util.regex.matcher;import Java.util.regex.pattern;public class Demo {public static void main (        String[] args) {//method1 ();//Match//method2 ();//Cut//method3 ();//replace///The front is just a string method */    METHOD4 ();        } public static void Method1 () {String QQ = "1881265";        String regex1 = "[1-9]\\d{4,14}";  SYS (Qq.matches (REGEX1));        Whether to conform to the regex rule String s = "E";  String regex = "[A-za-z]";   The letter//string regex = "[a-d[m-p]]";     A to D or M to p/* \d number [0-9] * \d non-numeric [^0-9] * \s whitespace character * \s non-whitespace character * \w      Word character [a-za-z0-9_] * \w non-word character * * * * X? Once or 0 times * x* 0 times or more * x+ once or more * x{n} exactly n times * x{n,} at least n times * x{n,m} n times to M            Times * */String regex = "\\d";    SYS (s.matches (regex)); } public static void Method2 () {/*string s = "Zhang Li san";        String regex = "\\s+";        string[] arr = s.split (regex);        for (string ss:arr) sys (SS); */* String s = "Zhang.li.san";  String regex = "\ \.";                                                                                                           \. Represents any character in the regular expression, \ \. Represents the ordinary point,        cannot be used directly. Cut, it is special character string[] arr = s.split (regex);        for (String Ss:arr) sys (SS); *//*string s = "Www\\abs\\1.txt";          String regex = "\\\\";        string[] arr = s.split (regex);        for (string ss:arr) sys (SS); */String s = "Wekkyduffopxxxs"; Cut by overlapping words/* to complete the cut by overlapping words, in order for the rule to be reused, the rules can be encapsulated into a group, complete with (), the groups are numbered, starting from 1 */String regex = "(.) \\1+ ";        Parentheses are the concept of a group, \1 is re-appearing, \1+ is one or more string[] arr = s.split (regex);    for (String Ss:arr) sys (SS);  } public static void Method3 () {String s = "wj3374zns399nvn9999klf3333";  Replace number with # # String regex = "[0-9]";      S.replaceall (Regex, "#");        SYS (s);  /*string s = "Wekkyduffopxxxs"; Replace the overlapping words with a single, such as: zzzz->z String regex = "(.)        \\1+ ";        S.replaceall (Regex, "$");        SYS (s); */} public static void Method4 () {String s = "Zhas ASB cjcdj CSJ Cbbdv";        String regex = "[A-z]{3}";        Encapsulates a rule into an object Pattern p = pattern.compile (regex);        Gets the match object Matcher m = P.matcher (s); SYS (m.matches ());  Match all, false, note: The pointer moves backwards, affecting the following result while (M.find ()) {sys (m.group ())); Match to the string sys (M.start () + "..." +m.end ());    Matches the string to the beginning and end of the}} public static void Sys (Object obj) {System.out.println (obj); }}

Summary of Java Regular Expressions