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almokhtar bekkour
almokhtar bekkour

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8 ruby metaprogramming examples

Metaprogramming is a powerful technique in the Ruby programming language that allows developers to write code that can manipulate or generate other code at runtime. Here are ten examples of metaprogramming in Ruby:

Defining methods dynamically: Ruby allows developers to define methods on the fly using the define_method method. This can be useful for creating methods with similar behavior but different names, or for defining methods based on user input.

Using "method missing" to handle undefined methods: Ruby allows developers to define a special method named "method_missing" that is invoked whenever an undefined method is called. This can be used to provide a default behavior for undefined methods, or to implement functionality such as method overloading.

Using "constant missing" to handle undefined constants: Similar to method_missing, Ruby also allows developers to define a "constant_missing" method that is invoked whenever an undefined constant is accessed. This can be used to implement lazy loading or other advanced behavior.

Using "class_eval safe" to define methods on classes: Ruby's class_eval method allows developers to define methods on a class, but it can also be dangerous because it allows arbitrary code to be executed. The class_eval_safe method provides a safer alternative that allows developers to define methods without the risk of executing arbitrary code.

Using "instance_eval" to define methods on instances: The instance_eval method allows developers to define methods on a specific instance of an object, rather than on the object's class as a whole. This can be useful for creating methods that are specific to a particular instance, or for defining methods that use instance variables.

Using "define_singleton_method" to define methods on singleton classes: Ruby allows developers to define methods on the "singleton class" of an object, which is a special class that is associated with a specific instance of an object. This can be useful for creating methods that are specific to a particular instance, or for defining methods that use instance variables.

Using "eval" to execute code dynamically: The eval method allows developers to execute Ruby code that is defined as a string at runtime. This can be useful for implementing features such as a command-line interface or a scripting language within a Ruby application.

Using "send" to invoke methods dynamically: The send method allows developers to invoke a method on an object by name, rather than by statically calling the method. This can be useful for implementing functionality such as dynamic dispatch or method overloading.

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