Question

If I have arr = [1, 2, 3, 4] I know I can do the following…

> arr.each_slice(2) { |a, b| puts "#{a}, #{b}" }
1, 2
3, 4

…And…

> arr.each_with_index { |x, i| puts "#{i} - #{x}" }
0 - 1
1 - 2
2 - 3
3 - 4

…But is there a built in way to do this?

> arr.each_slice_with_index(2) { |i, a, b| puts "#{i} - #{a}, #{b}" }
0 - 1, 2
2 - 3, 4

I know I can built my own and stick it into the array method. Just looking to see if there is a built in function to do this.

Answer 1

Like most iterator methods, each_slice returns an enumerable when called without a block since ruby 1.8.7+, which you can then call further enumerable methods on. So you can do:

arr.each_slice(2).with_index { |(a, b), i| puts "#{i} - #{a}, #{b}" }