Why do i get 'nomethoderror: undefined method for array'?

Example:

  arr = [1, 2, 3]
  arr.custom_method
  

Solution:

The method you're trying to use might not exist for the Array class. Ensure you're using the right method or define it if it's custom.

  class Array
    def custom_method
      # your method logic
    end
  end
  arr.custom_method