Refactor code with Stream API and modernize object comparisons.

Replaced loops and collections manipulations with Stream API in `LoopsSortsAndIfs` for better readability and performance. Updated `AntarcticaTimeZones` to use `toList()` instead of `collect`. Simplified `Golfer` equals method using `Objects.equals`.

src/main/java/datetime/AntarcticaTimeZones.java

@@ -4,7 +4,6 @@
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
 import java.util.List;
-import java.util.stream.Collectors;
 
 import static java.util.Comparator.comparingInt;
 
@@ -18,7 +17,7 @@ public static void main(String[] args) {
                         .map(now::atZone) // Stream<ZonedDateTime>
                         .sorted(comparingInt(
                                 zoneId -> zoneId.getOffset().getTotalSeconds()))
-                        .collect(Collectors.toList());
+                        .toList();
 
         antarcticZones.forEach(zdt ->
                 System.out.printf("UTC%6s: %25s %7s%n", zdt.getOffset(), zdt.getZone(),

src/main/java/refactoring/after/LoopsSortsAndIfs.java

@@ -1,30 +1,15 @@
 package refactoring.after;
 
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Comparator;
-import java.util.List;
+import java.util.*;
 
 public class LoopsSortsAndIfs {
     public static void main(String[] args) {
-        String[] strings = "this is an array of strings".split(" ");
 
-        List<String> evenLengths = new ArrayList<>();
-        for (String s : strings) {
-            if (s.length() % 2 == 0) {
-                evenLengths.add(s.toUpperCase());
-            }
-        }
-
-        Collections.sort(evenLengths, new Comparator<String>() {
-            @Override
-            public int compare(String s1, String s2) {
-                return s1.length() - s2.length();
-            }
-        });
-
-        for (String s : evenLengths) {
-            System.out.println(s);
-        }
+        Arrays.stream("this is an array of strings".split(" "))
+                .filter(s -> s.length() % 2 == 0)
+                .map(String::toUpperCase)
+                .sorted(Comparator.comparingInt(String::length)
+                        .thenComparing(Comparator.naturalOrder()))
+                .forEach(System.out::println);
     }
 }

src/main/java/sorting/Golfer.java

@@ -1,5 +1,7 @@
 package sorting;
 
+import java.util.Objects;
+
 public class Golfer implements Comparable<Golfer> {
     private String first;
     private String last;
@@ -54,8 +56,8 @@ public boolean equals(Object o) {
 
         Golfer golfer = (Golfer) o;
 
-        if (first != null ? !first.equals(golfer.first) : golfer.first != null) return false;
-        return last != null ? last.equals(golfer.last) : golfer.last == null;
+        if (!Objects.equals(first, golfer.first)) return false;
+        return Objects.equals(last, golfer.last);
 
     }