Accessing private methods in Ruby is generally discouraged as it breaks the encapsulation principle of object-oriented programming. But there are some ways to access private methods. In Ruby the methods can marked as private, this means they can not be called with an explicit receiver. This helps ensure that the method is only used within the defined class. There might be scenarios where you need to access these private methods such as for testing, and debugging. In this article, we explain How to access the private method in Ruby with related examples for your reference.

Prerequisites

To follow along with this guide, you should have

• Basic understanding of Ruby programming
• Ruby environment set on your system
• Object Oriented Programming concepts.
• Access key words

Using the send() method in ruby can be used to call private methods. This method allows us to bypass the usual visibility rules.

The Other one is instance_eval or class_eval. These methods can evaluate a block of code within the context of an instance or a class giving access to private methods and variables.

Example 1

By using the send method we can access the private methods in Ruby. Below we provide a related example.

class MyClass
  def initialize
    @secret = "Top Secret"
  end
  
  private
  
  def private_method
    "This is a private method"
  end
end

# Creating an instance of MyClass
obj = MyClass.new

# Attempting to call the private method directly will result in an error
# obj.private_method  # => NoMethodError

# Using send to call the private method
puts obj.send(:private_method)  # => "This is a private method"

This is a private method

Example 2

By using instance_eval method we can access the private methods in Ruby. Below we provide related example.

class MyClass
  def initialize
    @secret = "Top Secret"
  end
  
  private
  
  def private_method
    "This is a private method"
  end
end

# Creating an instance of MyClass
obj = MyClass.new

# Using instance_eval to call the private method
result = obj.instance_eval { private_method }
puts result  # => "This is a private method"

This is a private method

Example 3

By using class_eval method we can access the private methods in Ruby. Below we provide related example.

class MyClass
  def initialize
    @secret = "Top Secret"
  end
  
  private
  
  def private_method
    "This is a private method"
  end
end

# Using class_eval to redefine the visibility of the private method
MyClass.class_eval do
  public :private_method
end

# Now you can call the method directly
obj = MyClass.new
puts obj.private_method  # => "This is a private method"

This is a private method

Conclusion

Accessing private methods in Ruby is possible using techniques like send or instance_eval and class_eval. While these methods are powerful they should be used sparingly and primarily for testing and debugging purpose. Overusing these techniques can lead to code that is difficult to maintain and understand. As It breaks the encapsulation that private methods provided. And we provide related examples in the above.