CODEWITHSUNDEEP
javasortingcomparator
Kelsey Abreu
Kelsey Abreu

Reputation: 1124

Sort Arraylist by property of object

So I would like to sort everything out in my ArrayList by using the objects String Name that I have assigned to it.

So far I've read about Comparators to get what I want done. But when I implement it, I get a compile error.

I initialize it like this

private static ArrayList<PeopleInfo> infoArray = new ArrayList<PeopleInfo>();

and call the sort like this

Collections.sort(infoArray, new CustomComparator());

and this is the Class.

public class CustomComparator implements Comparator<PeopleInfo> {
    @Override
    public int compare(PeopleInfo o1, PeopleInfo o2) {
        return o1.GetLast().compareTo(o2.GetLast());
    }
}

The error I get is "No enclosing instance of type mainClass is accessible. Must qualify the allocation with an enclosing instance of type mainClass (e.g. x.new A() where x is an instance of MainClass)."

Not really understanding what's happening. Thanks in advance!

Upvotes: 1

Views: 1285

Answers (2)

Satheesh Cheveri
Satheesh Cheveri

Reputation: 3679

Alternatively you can declare comparator outside main class.

Upvotes: 0

Sameer
Sameer

Reputation: 4389

Declare your Comparator class as a static class

public static class CustomComparator implements Comparator<PeopleInfo> {

Upvotes: 3

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