array_methods/in_place_and_walks.rb

tests/_examples/array_methods/in_place_and_walks.rb in the metorex repository.

numbers = [3, 1, nil, 2]
p numbers.compact!
p numbers
p numbers.compact!
p numbers.sort!
p numbers.reverse!
p numbers.map! { |value| value * 2 }
p numbers.reject! { |value| value > 4 }
p numbers.select! { |value| value > 0 }
p numbers.uniq!
p [1, 1, 2].uniq { |value| value }

p [1, 2, 3].rotate
p [1, 2, 3].rotate(2)
p [1, [2, [3, [4]]]].flatten
p [1, [2, [3, [4]]]].flatten(1)

p [10, 20, 30].at(1)
p [10, 20, 30].at(-1)
p [10, 20, 30].at(9)
p [:a, :b, :b].count
p [:a, :b, :b].count(:b)
p [1, 2, 3].count { |value| value.odd? }
p [1, 2, 3, 1].take_while { |value| value < 3 }
p [1, 2, 3, 1].drop_while { |value| value < 3 }
p ["333", "2", "60"].minmax
p [6, 4, 10].min
p [6, 4, 10].max { |left, right| right <=> left }

p [1, 2, 3].each.class.to_s
p [1, 2, 3].map.class.to_s
p [1].eql?([1.0])
p [1].eql?([1])

class Stack < Array
  def initialize(first, second)
    self << first << second
  end
end

stack = Stack.new(1, 2)
p stack
p stack.class
p stack.size
p stack == [1, 2]
stack << 3
p stack.to_a
p Stack[7, 8, 9].to_a

cycle = []
cycle << cycle
p cycle
p cycle == cycle

grown = [1, 2, 3]
seen = []
grown.each do |value|
  seen << value
  grown << 4 if value == 3 && grown.size == 3
end
p seen

Output:

[3, 1, 2]
[3, 1, 2]
nil
[1, 2, 3]
[3, 2, 1]
[6, 4, 2]
[4, 2]
nil
nil
[1, 2]
[2, 3, 1]
[3, 1, 2]
[1, 2, 3, 4]
[1, 2, [3, [4]]]
20
30
nil
3
2
2
[1, 2]
[3, 1]
["2", "60"]
4
4
"Enumerator"
"Enumerator"
false
true
[1, 2]
Stack
2
true
[1, 2, 3]
[7, 8, 9]
[[...]]
true
[1, 2, 3, 4]