Java: moving items in array

Question

I\'m looking to move things around within an Array.

I want to be able to move the last item within the given Array to a spot while moving those in the current locati

Answer 1

Here's a more efficient and concise solution, relying on the natively implemented System.arraycopy:

public static void moveLastup(String[] arr, int pos) {
    String last = arr[arr.length-1];

    // Copy sub-array starting at pos to pos+1
    System.arraycopy(arr, pos, arr, pos + 1, arr.length - pos - 1);

    arr[pos] = last;
}

And some test code:

public static void main(String[] args) {
    String[] test = { "one", "two", "three", "four", "five" };

    // Move "five" to index 2
    moveLastup(test, 2);

    // [one, two, five, three, four]
    System.out.println(Arrays.toString(test));
}

---

Regarding your edit: You're working with and modifying the original array. If you want to "start over" in each moveLastup you need to work on a copy. This snippet prints what you want:

String[] list = { "a", "b", "c", "d", "e" };

for (int pos = 0; pos < list.length; pos++) {
    String[] tmpCopy = list.clone();
    moveLastup(tmpCopy, pos);
    showList(tmpCopy);
}

Output:

[e, a, b, c, d]
[a,e, b, c, d]
[a, b,e, c, d]
[a, b, c,e, d]
[a, b, c, d,e]