java shift elements in array

Question

Hey I am trying to shift elements forward sending the last element in the array to data[0]. I did the opposite direction but I can't seem to find my mistake in going in this direction.

Pos is users inputed shift times amount temp is the temporary holder. data is the array

if(pos > 0)
{
   do
   {
        temp = data[data.length -1];

        for(int i =0; i < data.length; i++)
        {
           if(i == data.length-1)
           {
              data[0] = temp; 
           }
           else
           {
               data[i+1] = data[i];
           }
        }

        pos--;
   } while(pos > 0);
}

Thanks.

This question should help you! https://stackoverflow.com/questions/7970857/shifting-elements-in-an-array — lezed1, Jun 11 '14 at 03:24
First, you don't need the `if` at the beginning of a `do-while` loop; it goes at the end. — Aarowaim, Jun 11 '14 at 03:24

score 0 · Answer 1 · edited May 23 '17 at 11:57

0

A good idea is to use System.arraycopy.

Please refer to this question Java, Shifting Elements in an Array

edited May 23 '17 at 11:57

Community

1
1

answered Jun 11 '14 at 03:25

Bruno Volpato

1,382
10
18

score 0 · Answer 2 · answered Jun 11 '14 at 03:41

0

try this

    int temp = data[data.length - 1];
    for (int i = data.length - 1; i > 0; i--) {
        data[i] = data[i - 1];
    }
    data[0] = temp;

or this

    int temp = data[data.length - 1];
    System.arraycopy(data, 0, data, 1, data.length - 1);
    data[0] = temp;

answered Jun 11 '14 at 03:41

Evgeniy Dorofeev

133,369
30
199
275

Your for does not work, and I am not aloud to use array.copy; – Jun 11 '14 at 23:41
Ok so It does work its EXACTLY what I needed, but why is it temp = data.length -1 and not data.length? I had data.length which error before. Can you please explain that for me? Thanks a bunch! – Jun 12 '14 at 00:43
array index starts from 0, if we have int[] a = {1, 2, 3}; then to access last element we use a[2] – Evgeniy Dorofeev Jun 12 '14 at 03:26

java shift elements in array

2 Answers2