Issues with reversing an array

Question

public static void reversedArray(double testArray[])
{
    double lastNumber = 0;
    for (int counter1 = 0, counter2 = testArray.length - 1; counter1 < testArray.length; counter1++, counter2 \--)
    {
       lastNumber = testArray[counter2];
       testArray[counter1] = testArray[counter2];
       testArray[counter2] = lastNumber;
    }
}

This is the method that reverses the array. The array is a length of 5. It correctly displays the first 3 numbers, but the last 2 numbers are wrong. E.g., I enter 1,2,3,4,5 and it returns 5,4,3,4,5

Edit: Looks like I got it, I took out the testArray.length as the comparison in the for loop and replaced it with counter2.

What language is this? I'm inclined to say Java, but am only 99% sure. — skiwi, Mar 02 '14 at 19:58

Jakub H · Accepted Answer · 2014-03-02T20:46:55.793

1

You are overwriting data in your array. You need some temporary location to store it. Now you should be able to fix your method yourself.

Next time consider to use Collections.reverse(Arrays.asList(yourArray)) instead of writing it by your own.

edited Mar 02 '14 at 20:46

answered Mar 02 '14 at 20:13

Jakub H

2,130
9
16

score 0 · Answer 2 · answered Mar 02 '14 at 20:10

0

Should be

  lastNumber = testArray[counter2];
  testArray[counter2] = testArray[counter1];
  testArray[counter1] = lastNumber;

answered Mar 02 '14 at 20:10

Tyler Brabham

218
2
8

no, it shouldn't be like that. have you checked your answer? – Jakub H Mar 02 '14 at 20:11
Indeed I have not. That's not the only issue with his code, but certainly one issue. – Tyler Brabham Mar 02 '14 at 20:16

Issues with reversing an array

2 Answers2