monkey_patching.rb

# Example 1: Monkey patching the String class
class String
  def to_b
    return true if self == "true"
    return false if self == "false"
    raise ArgumentError.new("invalid value for Boolean: #{self}")
  end
end

# Usage:
puts "true".to_b # outputs: true
puts "false".to_b # outputs: false
puts "foo".to_b # raises ArgumentError: invalid value for Boolean: foo


# Example 2: Monkey patching the Array class
class Array
  def sum
    self.inject(0) { |sum, x| sum + x }
  end
end

# Usage:
puts [1, 2, 3].sum # outputs: 6
puts [4, 5, 6].sum # outputs: 15


# Example 3: Monkey patching the Hash class
class Hash
  def keys_to_strings
    new_hash = {}
    self.each { |k, v| new_hash[k.to_s] = v }
    new_hash
  end
end

# Usage:
h = { name: "John", age: 30 }
puts h.keys_to_strings # outputs: {"name"=>"John", "age"=>30}