java pattern matching

1import java.util.regex.*;  
2public class RegexExample1{  
3public static void main(String args[]){  
4//1st way  
5Pattern p = Pattern.compile(".s");//. represents single character  
6Matcher m = p.matcher("as");  
7boolean b = m.matches();  
8  
9//2nd way  
10boolean b2=Pattern.compile(".s").matcher("as").matches();  
11  
12//3rd way  
13boolean b3 = Pattern.matches(".s", "as");  
14  
15System.out.println(b+" "+b2+" "+b3);  
16}}  

1import java.io.*;
2import java.util.*;
3import java.util.Collections;
4import java.util.regex.*;
5
6public class Solution {
7
8    public static void main(String[] args) {
9        Scanner scanner = new Scanner(System.in);
10        int num = scanner.nextInt();
11        String emailRegEx = ".+@gmail\\.com$";
12        Pattern pattern = Pattern.compile(emailRegEx);
13        List<String> list = new ArrayList();
14        for (int i = 0; i < num; i++){
15            String name = scanner.next();
16            String email = scanner.next();
17            Matcher matcher = pattern.matcher(email);
18            if (matcher.find()){
19                list.add(name);
20            }
21        }
22        Collections.sort(list);
23        for (String name : list){
24            System.out.println(name);
25        }
26    }
27}
28

1static void testTriangle(Shape s) {
2    switch (s) {
3        case Triangle t && (t.calculateArea() > 100) ->
4            System.out.println("Large triangle");
5        case Triangle t ->
6            System.out.println("Small triangle");
7        default ->
8            System.out.println("Non-triangle");
9    }
10}