Return an array of Pairs which have the same length as the input array of Strings. (Java)

Question

I want to create a class that would return an array of pairs that have the same length as the input array of strings. In addition, the pair should have the first letter of the string and length of the string.

for example; create(new String[] {"clue", "yay", "neon", "halala"}) should return the array of Pairs {[’c’,4],[’y’,3],[’n’,4],['h',6]}

So, my input and output would both be arrays. But the output has to be in the form of a pair. Here's what i tried:

import java.util.Arrays;



public class Couple {


public static Couple[] create(String[] source){

        for (int i = 0; i < source.length; i++) {

            System.out.print("["+","+source.length+"]") ;
        }
        return null;

    }            

    public static void main(String[] args) {
        System.out.println(Arrays.toString(create(new String[] {"clue", "yay", "neon", "halala"})));

    }

}

as it's obvious there are a few errors+ i dont want it to return null. But just for the sake of testing this code, i had to do it. Any ideas?

Answer 1

public class Couple {

    private char firstChar;
    private int length;

    public Couple(char firstChar, int length) {
        this.length = length;
        this.firstChar = firstChar;
    }

    public static Couple[] create(String[] source) {
        Couple[] couples = new Couple[source.length]; // create the array to hold the return pairs

        for (int i = 0; i < source.length; i++) {
            String entry = source[i];
            if (entry != null) {
                couples[i] = new Couple(entry.charAt(0), entry.length());
            } else {
                // What do you want to do if there's a null value?
                // Until you answer this we'll just leave the corresponding Couple null aswell
            }
        }

        return couples;
    }

    @Override
    public String toString() {
        return "Couple{" +
                "firstChar=" + firstChar +
                ", length=" + length +
                '}';
    }
}