max.rb

require 'pry'
# Find the maximum 
def maximum(arr)
# arr.max
  big = arr[0]

  arr.each do |x|
    big = x if big < x
  end
  big
end

# expect it to return 42 below
result = maximum([2, 42, 22, 02])
puts "max of 2, 42, 22, 02 is: #{result}"

# expect it to return nil when empty array is passed in
result = maximum([])
puts "max on empty set is: #{result.inspect}"

#expect 0
result = maximum([-23, 0, -3])
puts "max of -23, 0, -3 is: #{result}"

#expect 6
result = maximum([6])
puts "max of just 6 is: #{result}"


## expected output
# max of 2, 42, 22, 02 is: 42
# max on empty set is: nil
# max of -23, 0, -3 is: 0
# max of just 6 is: 6