Andi - 1 year ago 38

Ruby Question

How can i iterate over a ruby array and always get two values, the current and the next, like:

`[1,2,3,4,5,6].pairwise do |a,b|`

# a=1, b=2 in first iteration

# a=2, b=3 in second iteration

# a=3, b=4 in third iteration

# ...

# a=5, b=6 in last iteration

end

My usecase: I want to test if an array is sorted, and by having an iterator like this i could always compare two values.

I am not searching for

`each_slice`

Answer

You are looking for `each_cons`

:

```
(1..6).each_cons(2) { |a, b| p a: a, b: b }
# {:a=>1, :b=>2}
# {:a=>2, :b=>3}
# {:a=>3, :b=>4}
# {:a=>4, :b=>5}
# {:a=>5, :b=>6}
```

Source (Stackoverflow)