A Java collection of value pairs tuples

0 votes

What I'm looking for is a type of collection where each element in the collection is a pair of values. Each value in the pair can have its own type (like the String and Integer example above), which is defined at declaration time.

The collection will maintain its given order and will not treat one of the values as a unique key (as in a map).

Essentially I want to be able to define an ARRAY of type <String,Integer> or any other 2 types.

I realize that I can make a class with nothing but the 2 variables in it, but that seems overly verbose.

I also realize that I could use a 2D array, but because of the different types I need to use, I'd have to make them arrays of OBJECT, and then I'd have to cast all the time.

I only need to store pairs in the collection, so I only need two values per entry. Does something like this exist without going the class route?

Jul 2, 2018 in Java by Sushmita
• 6,910 points
2,198 views

1 answer to this question.

0 votes
The Pair class is one of those "gimme" generics examples that is easy enough to write on your own. 
public class Pair<L,R> {

  private final L left;
  private final R right;

  public Pair(L left, R right) {
    this.left = left;
    this.right = right;
  }

  public L getLeft() { return left; }
  public R getRight() { return right; }

 
@Override
  public int hashCode() { return left.hashCode() ^ right.hashCode(); }

  @Override
  public boolean equals(Object o) {
    if (!(o instanceof Pair)) return false;
    Pair pairo = (Pair) o;
    return this.left.equals(pairo.getLeft()) &&
           this.right.equals(pairo.getRight());
  }

}

answered Jul 2, 2018 by sharth
• 3,370 points

Related Questions In Java

0 votes
1 answer

How do I create a Java string from the contents of a file?

If you're looking for an alternative that ...READ MORE

answered Apr 19, 2018 in Java by Rishabh
• 3,620 points
945 views
0 votes
2 answers

Counting no of Occurrence of a particular character inside a string in Java

We can find out the no. of ...READ MORE

answered Sep 7, 2018 in Java by Sushmita
• 6,910 points
2,310 views
0 votes
2 answers

How can I sort values of a Map in Java using its key

Assuming TreeMap is not good for you ...READ MORE

answered Oct 10, 2018 in Java by Sushmita
• 6,910 points
919 views
0 votes
1 answer

The best way to filter a Java Collection?

 this problem is solved using streams and ...READ MORE

answered May 29, 2018 in Java by Parth
• 4,630 points
657 views
0 votes
1 answer

How to use pairs or 2-tuples in java?

You can refer the following code: public class ...READ MORE

answered Jun 7, 2018 in Java by Daisy
• 8,120 points
536 views
0 votes
2 answers

Ho do I Iterate through a HashMap which contains duplicate values

for (Map.Entry<String, String> item : params.entrySet()) { ...READ MORE

answered Jul 24, 2018 in Java by samarth295
• 2,220 points
4,824 views
0 votes
2 answers

Performing Iteration over each entry in a 'Map'

In Java 8 you can do it ...READ MORE

answered Oct 24, 2018 in Java by Sushmita
• 6,910 points
800 views
0 votes
2 answers
+1 vote
3 answers

Copy Java Array and make a duplicate of it

int[] a = {1,2,3,4,5}; int[] b = Arrays.copyOf(a, ...READ MORE

answered Aug 30, 2018 in Java by Sushmita
• 6,910 points
1,372 views
0 votes
2 answers

Get all the permutations of a string in Java

You could use recursion to do this.  Try ...READ MORE

answered Aug 21, 2019 in Java by Sirajul
• 59,230 points
1,849 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP