mitch =

age:    21
height: 180cm
pets:   [\dog, \goldfish]

phile = {} phile{height, pets} = mitch phile.height #=> 180 phile.pets #=> [‘dog’, ‘goldfish’]

a = [2 7 1 8]

..push 3
..shift!
..sort!

a #=> [1,3,7,8]