JAVA

java regex

import java.util.regex.*;  
public class RegexExample1{  
public static void main(String args[]){  
//1st way  
Pattern p = Pattern.compile(".s");//. represents single character  
Matcher m = p.matcher("as");  
boolean b = m.matches();  
  
//2nd way  
boolean b2=Pattern.compile(".s").matcher("as").matches();  
  
//3rd way  
boolean b3 = Pattern.matches(".s", "as");  
  
System.out.println(b+" "+b2+" "+b3);  
}}  

java regex

/*
The Java Regex or Regular Expression is an API to define a pattern for searching 
or manipulating strings.
*/

// Regex Character classes
1. [abc] ----- a, b, or c (simple class)
2. [^abc]   -- Any character except a, b, or c (negation)
3. [a-zA-Z] -- a through z or A through Z, inclusive (range)  
4. [a-d[m-p]] --  a through d, or m through p: [a-dm-p] (union) 
5. [a-z&&[def]] -- d, e, or f (intersection)
6. [a-z&&[^bc]]  -- a through z, except for b and c: [ad-z] (subtraction)
7. [a-z&&[^m-p]] -- a through z, and not m through p: [a-lq-z](subtraction)

Please click source link for more details

regular expression java

//Ther are three type of REGULAR EXPRESSION     
   //first
   ^(.+)@(.+)$   "^(.+)@(.+)$""
   //second
   ^[A-Z0-9._%+-]+@[A-Z0-9.-]+.[A-Z]{2,6}$
     //third
   ^[w!#$%&'*+/=?`{|}~^-]+(?:.[w!#$%&'*+/=?`{|}~^-]+)*@(?!-)(?:[a-zA-Z0-9-]+.)+[a-zA-Z]{2,6}$  

regex java

package RegexMainNMD;
//NMD
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class RegexNMDSE {
    public static void main(String[] args) {
        String strTest = "Regex 15-05-2020, Nguyen Minh Duc 16/02/1998. Deadline 18_02_2020";
        Pattern patternDate = Pattern.compile("d{2}[-|/]d{2}[-|/]d{4}");
        Matcher matcher = patternDate.matcher(strTest);
         
        System.out.println("Ngày tháng năm trong chuỗi đầu vào: " + strTest +" là:");
        while(matcher.find()) {
            System.out.println(strTest.substring(matcher.start(), matcher.end()));
        }         
        String strTest2 = "15/05/2020";
        String strTest3 = "16/02/mdse";
        patternDate = Pattern.compile("^d{2}[-|/]d{2}[-|/]d{4}$");
        System.out.println("Chuỗi " + strTest2 + " có định dạng ngày tháng: "
                + patternDate.matcher(strTest2).matches());
         
        System.out.println("Chuỗi " + strTest3 + " có định dạng ngày tháng: "
                + patternDate.matcher(strTest3).matches());
    } 
}

Java Regular Expressions

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

public class Main {
  public static void main(String[] args) {
    Pattern pattern = Pattern.compile("w3schools", Pattern.CASE_INSENSITIVE);
    Matcher matcher = pattern.matcher("Visit W3Schools!");
    boolean matchFound = matcher.find();
    if(matchFound) {
      System.out.println("Match found");
    } else {
      System.out.println("Match not found");
    }
  }
}
// Outputs Match found

java regex

Pattern pattern = Pattern.compile("1");
Matcher matcher = pattern.matcher("111");
while (matcher.find()) {
    System.out.println(matcher.group());
}