Ruby, like other programming languages suchas Go, JavaScript, PHP, Lua and Python, allows several variables to be assigned in parallel. This is called parallel assignment 1 .
array = [1, 2, 3]
left_index = 0
right_index = -1
array[left_index], array[right_index] = array[right_index], array[left_index]
p array # => [3, 2, 1]The idiom on line 5 is used to swap two values without the use of an intermediate variable. Good to know.
Also called simultaneous assignment or sometimes **multiple