1. x
>
Array.new(5)
[nil, nil, nil, nil, nil]
>
x = Array.new(5)
nil
nil
[nil, nil, nil, nil, nil]
>
x[1] = 999

2. x
>
Array.new(5)
[nil, nil, nil, nil, nil]
>
x = Array.new(5)
nil
999
nil
[nil, nil, nil, nil, nil]
>
x[1] = 999
999
>

3. x
>
[1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = [1,2,3,4,5] 1 2 3 4 5 1 2 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999

4. x
>
[1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = [1,2,3,4,5] 1
999 3 4 5 1 2 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999
999
>

5. y x
>
y = [1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = [1,2,3,4,5] 1 2 3 4 5 1 2 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999

6. y x
>
y = [1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = [1,2,3,4,5] 1
999 3 4 5 1 2 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999
999
>
y[1] 2
>

7. y x
>
y = [1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = y 1 2 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999

8. y x
>
y = [1,2,3,4,5]
[1, 2, 3, 4, 5]
>
x = y 1
999 3 4 5
[1, 2, 3, 4, 5]
>
x[1] = 999
999
>
y[1]
999
>

9. x
0>
x = Array.new(5)
[nil, nil, nil, nil, nil]
0>
nil

10. x
0>
x = Array.new(5)
[nil, nil, nil, nil, nil]
0>
x[1] = Array.new(3)
nil
[nil, nil, nil]
0>
x[1][2] = 999
nil

11. x
0>
x = Array.new(5)
[nil, nil, nil, nil, nil]
0>
x[1] = Array.new(3)
nil
[nil, nil, nil]
0>
x[1][2] = 999
999
0>
nil
999

12. 0>
x = Array.new(5)
[nil, nil, nil, nil, nil]
0> x
nil

13. 0>
x = Array.new(5)
[nil, nil, nil, nil, nil]
0>
for i in 0..x.size-1
1> x[i] = Array.new(3)
1> end
0..4
0> x
nil
nil
nil
nil
nil