How to return multiple values?

Question

Is it possible to return two or more values from a method to main in Java? If so, how it is possible and if not how can we do?

Return array, list, set, map or your custom object containing multiple values. I have seen this same question somewhere.... let me find that. There are multiple questions on this topic: http://stackoverflow.com/search?q=return+multiple+values+in+java%3F — Harry Joy, Dec 19 '11 at 06:10
Maybe too late, but Just use java.util.AbstractMap.SimpleIEntry. Reusable, everywher since 1.6 — yerlilbilgin, Feb 04 '20 at 07:47
If you are on Java 14+, it is better in general to use a Java Record instead of a SimpleEntry for representing a pair of values. — Jason, Jan 30 '21 at 14:52

score 91 · Answer 1 · edited Nov 02 '18 at 15:45

91

You can return an object of a Class in Java.

If you are returning more than 1 value that are related, then it makes sense to encapsulate them into a class and then return an object of that class.

If you want to return unrelated values, then you can use Java's built-in container classes like Map, List, Set etc. Check the java.util package's JavaDoc for more details.

edited Nov 02 '18 at 15:45

biniam

8,099
9
49
58

answered Dec 19 '11 at 06:10

Aravind Yarram

78,777
46
231
327

I would add one more point to this - keep your returned object immutable (best initialize it in a constructor and keep your fields final) – Kris Dec 19 '11 at 13:35
4

You can return an object , but if you have so many return objects in your program it makes the source code complicated. for things that are returned from a method once-of-its-kind-it-the-program better to have Tuples. like c#. darling c# its a great language – EKanadily Aug 22 '15 at 22:41
1

I guess there should be C# `out` or `ref` parameter equivalent in Java, otherwise I will need to create class even for returning two variables and for each function returning multiple values. If we follow this, then there will be a class for every function returning multiple values. Though using `Map` feels better approach now. – Mahesha999 Sep 18 '15 at 08:52
I would use a map or set for keeping it simple :) – Saqib Javed Sep 21 '17 at 08:10
I think you mean `If you are returning more than 1 value that are un-related` and vice versa – User3 Nov 24 '17 at 10:12
3

Returning maps, lists or sets (to avoid returning a DTO) IMHO is an antipattern. – Lluis Martinez Jan 14 '19 at 17:18

score 41 · Answer 2 · edited Dec 19 '11 at 06:41

41

You can do something like this:

public class Example
{
    public String name;
    public String location;

    public String[] getExample()
    {
        String ar[] = new String[2];
        ar[0]= name;
        ar[1] =  location;
        return ar; //returning two values at once
    }
}

edited Dec 19 '11 at 06:41

yshavit

42,327
7
87
124

answered Dec 19 '11 at 06:17

RanRag

48,359
38
114
167

2

How performance efficient is this? – Aaron Franke Nov 02 '18 at 09:56

score 38 · Answer 3 · answered Dec 19 '11 at 06:10

38

You can only return one value, but it can be an object that has multiple fields - ie a "value object". Eg

public class MyResult {
    int returnCode;
    String errorMessage;
    // etc
}

public MyResult someMethod() {
    // impl here
}

answered Dec 19 '11 at 06:10

Bohemian

412,405
93
575
722

How to return multiple values?

3 Answers3

Linked

Related