new file Exercises

Exercises.java

@@ -0,0 +1,92 @@
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class Exercises {
+
+    /*
+        complete the method below, so it will validate an email address
+     */
+    public boolean validateEmail(String email) {
+        String regex ="^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@" + "(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$" ;
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(email);
+
+        return matcher.matches();
+    }
+
+    /*
+        this method should find a date in string
+        note that it should be in british or american format
+        if there's no match for a date, return null
+     */
+    public String findDate(String string) {
+        String regex = "(0[1-9]|[12][0-9]|3[01])[-/](0[1-9]|1[0-2])[-/](\\d{4})|\\d{4}[-/](0[1-9]|1[0-2])[-/](0[1-9]|[12][0-9]|3[01])";
+
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(string);
+
+        if (matcher.find()) {
+            return matcher.group();
+        }
+
+        return null;
+    }
+
+    /*
+        given a string, implement the method to detect all valid passwords
+        then, it should return the count of them
+
+        a valid password has the following properties:
+        - at least 8 characters
+        - has to include at least one uppercase letter, and at least a lowercase
+        - at least one number and at least a special char "!@#$%^&*"
+        - has no white-space in it
+     */
+    public int findValidPasswords(String string) {
+        String regex = "(?=.*[A-Z])(?=.*[a-z])(?=.*\\d)(?=.*[!@#$%^&*])[^\\s]{8,}";
+        Pattern pattern = Pattern.compile(regex);
+        Matcher matcher = pattern.matcher(string);
+        int v = 0;
+        String[] words = string.split(" ");
+        for (String word : words) {
+            if (matcher.reset(word).find()) {
+                v++;
+            }
+        }
+        return v;
+    }
+
+    /*
+        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<>();
+        string = string.replaceAll("[^a-zA-Z ]", "");
+        String[] words = string.split("\\s+");
+        for (String word : words) {
+            if (word.length() >= 3) {
+                String lowerWord = word.toLowerCase();
+                String reversed = new StringBuilder(lowerWord).reverse().toString();
+                if (lowerWord.equals(reversed)) {
+                    list.add(word);
+                }
+            }
+        }
+
+        return list;
+    }
+
+    public static void main(String[] args) {
+        Exercises ex = new Exercises();
+        System.out.println(ex.validateEmail("example@example.com"));
+        System.out.println(ex.findDate("12/09/2023"));
+        System.out.println(ex.findValidPasswords("P@ssw0rd test Invalid Pass1"));
+        List<String> palindromes = ex.findPalindromes("Madam, did you see Bob running? Kayak radar civic level");
+        System.out.println(palindromes);
+    }
+}