## |. y (Reverse)

Rearranges the items of list y in reverse order.

```   |. i.6
5 4 3 2 1 0```

y can be a matrix...

```   ] z=: 3 4 {. i.10 10         NB. sample noun
0  1  2  3
10 11 12 13
20 21 22 23

|.z                          NB. items are the rows of z
20 21 22 23
10 11 12 13
0  1  2  3

|."1 z                       NB. items are the numbers in each row
3  2  1  0
13 12 11 10
23 22 21 20```

## x |. y (Rotate (Shift))

Rotates the items of list y.

```   3 |. i.6
3 4 5 0 1 2

_1 |. i.6            NB. negative x -- other direction
5 0 1 2 3 4```

y can be a matrix...

```   ] z=: 6 4 {. i.10 10         NB. sample noun
0  1  2  3
10 11 12 13
20 21 22 23
30 31 32 33
40 41 42 43
50 51 52 53

3 |. z
30 31 32 33
40 41 42 43
50 51 52 53
0  1  2  3
10 11 12 13
20 21 22 23

_1 |."1 z
3  0  1  2
13 10 11 12
23 20 21 22
33 30 31 32
43 40 41 42
53 50 51 52```

### Common uses

Shift, instead of Rotate, by using Customize (!.).

The right-argument of Customize is your chosen fill-element (say, _)...

```   2 |.!._ i.6
2 3 4 5 _ _

_2 |.!._ i.6
_ _ 0 1 2 3```

If x is omitted, it defaults to _1 (yielding Right Shift by 1 element)...

```   |.!._ i.6
_ 0 1 2 3 4```