Procs Yielding to blocks from methods is the simplest way to access closures. However, yield is a bit limited, because it can only invoke the block directly. It can’t send the block somewhere else to be invoked. To do that, … Continued
Scope An entity’s scope is the area of the application in which it is “visible.” For example, a variable’s scope is the area of an application that can access the variable. And an object’s scope is the area of an … Continued
Methods With an Explicit Block Parameter A method that uses an explicit block parameter has these rules: Only one block parameter is allowed. It must be last parameter in the list. Its name must begin with &. The & tells … Continued
What are Blocks? Blocks in Ruby are chunks of code that are — almost — nothing but chunks of code. A block is not a method. It is not a proc or a lambda. And, despite the popular statement that … Continued
Inheritance Inheritance is a core concept in object-oriented design. For an overview of object-oriented design, have a look at Object-Oriented Design Basics: Objects, Classes and Inheritance. Inheritance is the ability of one class (a “subclass”) to use the state and … Continued
What is Polymorphism? Polymorphism is the ability to represent different sets of data and different behaviors with a common interface. Typically, this means two classes that have the same methods but different implementations of those methods. A good analogy is … Continued