void main() {
List names = List.of("Martin", "Lucy", "Peter",
"Martin", "Robert", "Peter");
System.out.println(unique(names));
System.out.println(unique2(names));
System.out.println(unique3(names));
}
List unique(List names) {
List uniqueNames = new ArrayList<>();
names.forEach(e -> {
if (!uniqueNames.contains(e)) {
uniqueNames.add(e);
}
});
return uniqueNames;
}
List unique2(List names) {
return names.stream().distinct().toList();
}
List unique3(List names) {
HashSet uniqueNames = new HashSet<>(names);
return new ArrayList(uniqueNames);
}