Transform a List<Object> to a Map such that the String is not a duplicate value using Java 8 Streams

Question

We have a Student class as follows:

class Student {
    private int marks;
    private String studentName;

    public int getMarks() {
        r         


        

Answer 1

That's because of an incorrect merge function, you should instead use:

Map map = studentList.stream()
        .collect(Collectors.toMap(
                student -> student.getStudentName().toLowerCase(),
                Student::getMarks,
                (s1, s2) -> s1 + s2, // add values when merging
                LinkedHashMap::new));