How do I switch the first term and the last term of an array?

Question

public class ArrayMethods {
    double[] array = new double[5];

    //swap the first and last elements in the array
    public void swap () {
       array[0]=array[4];
       array[4]=array[0];
       System.out.print(array);
    }
}

Here is my code so far. And this is what it is spiting out with of course random numbers

Original: [D@15db9742

[D@15db9742

but I want it to spit out

Original: 159742

259741

what you print is the value returned to you by the toString method. You shouldn't print the array, you should print it's contents. — Stultuske, Mar 07 '19 at 07:57
You'll also want to look at this for printing the array's content: https://stackoverflow.com/questions/409784/whats-the-simplest-way-to-print-a-java-array — ernest_k, Mar 07 '19 at 07:58

score 1 · Answer 1 · answered Mar 07 '19 at 07:58

1

You need to buffer one value and print it correctly:

public class ArrayMethods {
        double[] array = new double[5];

        //swap the first and last elements in the array
        public void swap () {
           double temp = array[0];
           array[0]=array[4];
           array[4]=temp;
           System.out.println(Arrays.toString(array));
        }
    }

answered Mar 07 '19 at 07:58

Markus Steppberger

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how does the print work – Austin Brown Mar 07 '19 at 08:02
array.toString() will give you the information of the array object which you do not really want here (hashcode). Arrays.toString(array) will print the content of the array instead of the object information of the array object itself. – Markus Steppberger Mar 07 '19 at 08:03
is it supposed to print [0.0, 0.0, 0.0, 0.0, 0.0] – Austin Brown Mar 07 '19 at 08:05
@AustinBrown yes, because you never populate the array with values, so for a `double` array, each element defaults to `0.0` – QBrute Mar 07 '19 at 08:08
Thank you guys soo much – Austin Brown Mar 07 '19 at 08:08

How do I switch the first term and the last term of an array?

1 Answers1