What it means "..." in this code?

Question

public class AcademGroup implements Serializable {
Student[] students;

AcademGroup(Student... st) {
    this.students = st;
}

What it means "Student... st"? Thank you.

score 3 · Accepted Answer · answered Dec 22 '13 at 11:50

This is the ellipsis operator.

It means you can pass an arbitrary number of arguments to your method/constructor when calling it. E.g.:

new AcademGroup(student1);
new AcademGroup(student1, student2);
new AcademGroup(student1, student2, student3);

etc. In the method/constructor's code it's treated as an array.

peter.petrov · Answer 2 · 2013-12-22T11:56:50.993

2

It means varargs. Any count of
students you can pass in there.

So you can call it like this

new AcademGroup();

or

new AcademGroup(st);

or

new AcademGroup(st1, st2);

or

new AcademGroup(st1, st2, st3);

and so on, i.e. with 0,1,2,3, etc.
Student objects as parameters.

edited Dec 22 '13 at 11:56

answered Dec 22 '13 at 11:48

peter.petrov

score 1 · Answer 3 · answered Dec 22 '13 at 11:49

1

It means that you can pass any amount of Student in there and st will result in an array or a sequence of Student.

answered Dec 22 '13 at 11:49

Octoshape

3 Answers3