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