Return an ArrayList and int value from a single method. Is it Possible?

Question

I'm working on my coursework and came up with this situation. Here's my code.

public static ArrayList<Student> checkPresent(String unitID, String week){
    int present = 0;
    ArrayList<Student> studentDetails = Student.getStudentDetails();

    ArrayList<AttendanceLog> pickedList = AttendanceLog.pickFromAttendanceLog(unitID, week);

    for(Student student : studentDetails){
        student.setPresent("N");
        for(AttendanceLog attendance : pickedList){
            if(student.getStudentNo().equals(attendance.getStudentID())){
                student.setPresent("Y");
                present++;
            }

        }
    }

    return studentDetails;

}

I have only returned the ArrayList but I also want to get the integer value present. Is it possible? Or how can I take the int value ?

you can encapsulate the arraylist and integer in a class and return its object — Hemang, Dec 31 '15 at 09:02
Possible duplicate of [How to return multiple objects from a Java method?](http://stackoverflow.com/questions/457629/how-to-return-multiple-objects-from-a-java-method) — ctomek, Jan 01 '16 at 14:56

dsp_user · Answer 1 · 2015-12-31T09:56:34.060

Yes, you can create a class which holds both an ArrayList as well as an integer

class SomeClass{
ArrayList<Student> aList;
int present;
}

and have your method return an instance of this class

UPDATE:

public static SomeClass checkPresent(String unitID, String week){

int present = 0;
ArrayList<Student> studentDetails = Student.getStudentDetails();

ArrayList<AttendanceLog> pickedList = AttendanceLog.pickFromAttendanceLog(unitID, week);

for(Student student : studentDetails){
    student.setPresent("N");
    for(AttendanceLog attendance : pickedList){
        if(student.getStudentNo().equals(attendance.getStudentID())){
            student.setPresent("Y");
            present++;
        }

    }
}
SomeClass someCls = new SomeClass();
someCls.present = present;
someCls.aList = studentDetails;
return someCls;

}

Note that in your example you're obtaining studentDetails statically, so it wouldn't make much sense to code it this way because you can always get the students list by calling Student.getStudentDetails().

Can you please explain it further more with a sample code ? – benuri_alwis Dec 31 '15 at 09:07 — benuri_alwis, Dec 31 '15 at 09:07
Thank you! It was really usefull – benuri_alwis Dec 31 '15 at 10:25 — benuri_alwis, Dec 31 '15 at 10:25

score 3 · Answer 2 · answered Dec 31 '15 at 09:02

You can only return one thing from a method.

You have to options :

pass the ArrayList as an argument to the method. The caller would instantiate the ArrayList and the method would populate it. Then your method can return the int you wish to return in addition to the ArrayList.
Wrap the ArrayList and int in some custom class and change your method to return an instance of that class (you can also do that with an Object[], but that would be ugly).

score 1 · Accepted Answer · answered Apr 27 '17 at 10:40

1

Create class holing the arraylist and the integer. classname name = new classname(); name.integerValue= integerValue; name.arraylist= arraylist; return arraylist;

answered Apr 27 '17 at 10:40

Lakshan G

366
3
9

score 0 · Answer 4 · answered Dec 31 '15 at 09:04

0

I like to create a new type that has the ArrayList and int as members.

class Result {
    public final int value;
    public final List<> list;

    public Result(int val, List<> list) {
        this.value = val;
        this.list = list;
}

answered Dec 31 '15 at 09:04

ayvazj

3,943
1
14
14

Return an ArrayList and int value from a single method. Is it Possible?

4 Answers4