Assign to an array and replace emerged nil values

Question

Greetings!

When assigning a value to an array as in the following, how could I replace the nils by 0?

array = [1,2,3]
array[10] = 2
array # => [1, 2, 3, nil, nil, nil, nil, nil, nil, nil, 2]

If not possible when assigning, how would I do it the best way afterwards? I thought of array.map { |e| e.nil? ? 0 : e }, but well…

Thanks!

Answer 1

To change the array after assignment:

array.map! { |x| x || 0 }

Note that this also converts false to 0.

If you want to use zeros during assignment, it's a little messy:

i = 10
a = [1, 2, 3]
a += ([0] * (i - a.size)) << 2
# => [1, 2, 3, 0, 0, 0, 0, 0, 0, 0, 2]

Answer 2

There is no built-in function to replace nil in an array, so yes, map is the way to go. If a shorter version would make you happier, you could do:

array.map {|e| e ? e : 0}