Reject (negative filter, grep)

• reject

• reject!

• filter

• grep

• the reject! with the exclamation mark will modify the array

• the reject without the exclamation mark will only return the filtered array

numbers = [10, 20, 7, 21, 5]
puts numbers
small = numbers.reject do |num|
  num > 10
end
puts small
puts numbers.reject { |num| num > 10 }
puts numbers
puts ""

big = numbers.reject! do |num|
  num < 10
end
puts big
puts numbers

[10, 20, 7, 21, 5]
[10, 7, 5]
[10, 7, 5]
[10, 20, 7, 21, 5]

[10, 20, 21]
[10, 20, 21]