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HW-02-git-and-java-practice/src/main/java/BonusExercises.java
T

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3.3 KiB
Java

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class BonusExercises {
/*
complete the method below, so it will validate an email address
1. Must have exactly one @ (no more, no less)
2. Split into local-part and domain (before @ and after @)
3. Local-part rules:
- Can't be empty
- Can't start or end with dot
- Can't have two dots in a row
4. Domain rules:
- Can't be empty
- Can't start or end with hyphen
- Can't have underscores
- Each segment (between dots) must follow same hyphen rules
*/
public boolean validateEmail(String email) {
String regex = "^[a-zA-z0-9_+-]+(?:\\.[a-zA-Z0-9_+-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z0-9-]+$";
Pattern pattern = Pattern.compile(regex);
Matcher matcher = pattern.matcher(email);
return matcher.matches();
}
/*
This method should find and return the first date in a string.
Supported formats:
- American: MM/DD/YYYY (e.g., 12/09/2023)
- British: DD/MM/YYYY (e.g., 12/09/2023 — same pattern, context matters)
- ISO: YYYY-MM-DD (e.g., 2024-07-15)
- Slash variant: YYYY/MM/DD (e.g., 2025/01/01)
If no match for a date is found in the string, return null.
*/
public String findDate(String string) {
String regex1 = "(0[1-9]|1[0-2])\\/(0[1-9]|[12][0-9]|30)\\/\\d{4}|(0[1-9]|[12][0-9]|30)\\/(0[1-9]|1[0-2])\\/\\d{4}";
String regex2 = "(\\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12][0-9]|30))";
String regex3 = "(\\d{4}\\/(0[1-9]|1[0-2])\\/(0[1-9]|[12][0-9]|30))";
Pattern pattern = Pattern.compile(regex1 + "|" + regex2 + "|" + regex3);
Matcher matcher = pattern.matcher(string);
if(matcher.find()){
return matcher.group();
}
return null;
}
/*
given a string, implement the method to detect all valid passwords
then, it should return the count of them
a valid password has the following properties:
- at least 8 characters
- has to include at least one uppercase letter, and at least a lowercase
- at least one number and at least a special char "!@#$%^&*"
- has no white-space in it
*/
public int findValidPasswords(String string) {
String regex = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\\d)(?=.*[!@#$%^&*]).{8,}$";
Pattern pattern = Pattern.compile(regex);
String[] parts = string.split("\\s+");
int counter = 0;
for(String part : parts){
Matcher matcher = pattern.matcher(part);
if(matcher.matches()){
counter++;
}
}
return counter;
}
/*
you should return a list of *words* which are palindromic
by word we mean at least 3 letters with no whitespace in it
note: your implementation should be case-insensitive, e.g. Aba -> is palindrome
*/
public List<String> findPalindromes(String string) {
List<String> list = new ArrayList<>();
// todo
return list;
}
public static void main(String[] args) {
// you can test your code here
}
}