Comment 1 Manoj N Palat 2021-04-05 00:19:41 EDT

@Felix: Could you please give a "before" and "after" code example ?

Comment 2 Felix Pahl 2021-04-05 05:15:00 EDT

Here are "before" and "after" code examples, as requested.

Simple case: The array is only used as a whole:

Before:

public class ArrayIndexReordering {
    public void useArray(int n) {
        int [] [] [] [] arr = new int [n] [4] [3] [2];
        for (int i = 0;i < n;i++)
            arr [i] [1] [2] [0] = 1;
    }
}

After swapping the first two and the last two indices:

public class ArrayIndexReordering {
    public void useArray(int n) {
        int [] [] [] [] arr = new int [4] [n] [2] [3];
        for (int i = 0;i < n;i++)
            arr [1] [i] [0] [2] = 1;
    }
}

More complicated case: Only some of the dimensions are allocated, and a subarray is passed:

Before:

import java.util.Arrays;

public class ArrayIndexReordering {
    public void useArray(int n) {
        int [] [] [] [] arr = new int [n] [4] [] [];
        for (int i = 0;i < n;i++)
            for (int j = 0;j < 4;j++)
                arr [i] [j] = new int [i + 3] [j + 2];
        System.out.println(Arrays.deepToString(arr [0] [1]));
    }
}

Here, the admissible permutations would have to permute the specified and unspecified indices among themselves. For instance, swapping the first two and the last two indices would still be allowed, and the result would be:

import java.util.Arrays;

public class ArrayIndexReordering {
    public void useArray(int n) {
        int [] [] [] [] arr = new int [4] [n] [] [];
        for (int i = 0;i < n;i++)
            for (int j = 0;j < 4;j++)
                arr [j] [i] = new int [j + 2] [i + 3];
        System.out.println(Arrays.deepToString(arr [1] [0]));
    }
}

Comment 3 Manoj N Palat 2021-04-05 09:11:35 EDT

Moving to ui as this is a refactoring request