How to remove zeroth index of array in ruby using pop function

Question

I have an array like:

a = Array.new([1,2,3,4,5,5,6,6,7,8])

By doing the following, I expect the output to be the zeroth index, which is popped out of the array.

a.pop
a.pop(0)

I am getting the output nil. Please give some suggestions on this behaviour.

You are not getting `nil` but `[]`, an array with 0 elements, right? — undur_gongor, Oct 06 '15 at 10:20
BTW, you can just write `a = [1,2,3,4,5,5,6,6,7,8]` to create an array. — Stefan, Oct 06 '15 at 10:20

undur_gongor · Answer 1 · 2015-10-22T11:12:40.817

4

The optional argument to pop is not the index to pop from but the number of elements to pop. They are always taken from the end of the array.

To take from the beginning you need shift.

edited Oct 22 '15 at 11:12

answered Oct 06 '15 at 10:18

undur_gongor

score 3 · Answer 2 · answered Oct 06 '15 at 10:18

3

.pop is removing elements from the right. To remove elements from the left, use .shift

a.shift

answered Oct 06 '15 at 10:18

Sergio Tulentsev

2 Answers2