✍️ List to Map @Getter @AllArgsConstructor public class MemberGrade { private String name; private String subject; private int grade; } 1. Simple Loop List memberGrades = new ArrayList(); memberGrades.add(new MemberGrade("침착맨", "수학", 100)); memberGrades.add(new MemberGrade("이말년", "수학", 90)); memberGrades.add(new MemberGrade("주호민", "수학", 80)); Map gradeMap = new HashMap(); for (MemberGrade mg : m..
✍️ List to Set 1. Java 8 Stream API List integerList = Arrays.asList(1, 1, 2, 3, 2, 1); Set integerSet = integerList.stream().collect(Collectors.toSet()); // [1, 2, 3] 2. Constructor List integerList = Arrays.asList(1, 1, 2, 3, 2, 1); Set integerSet = new HashSet(integerList); // [1, 2, 3] 3. addAll List integerList = Arrays.asList(1, 1, 2, 3, 2, 1); Set integerSet = new HashSet(); integerSet.ad..