![]() There is the overhead when reusing code that the creator of Erlang famously described as a case when you wanted a banana but you got a gorilla holding the banana. Some claimed that under OOP writing tests is harder and it requires extra care to refactor. Then the critics arrived on the scene, some of them quite disappointed. With OOP being followed by OOA (object-oriented analysis) and OOD (object-oriented design) it soon felt like everything you did in software had to be broken down to objects and their relationships to each other. ![]() After an initial hype period had promised improvements for modularising and organising large codebases, the idea was over applied. If they are used to top-down programming or functional programming, which treats elements of code as precise mathematical functions, it takes some getting used to. It is fair to say that, generations later, the idea of organizing your code into larger meaningful objects that model the parts of your problem continues to puzzle programmers. In contrast, many people who have experience with computers initially think there is something strange about object oriented systems.” “Many people who have no idea how a computer works find the idea of object-oriented programming quite natural. 10.In the August edition of Byte magazine in 1981, David Robson opens his article, which became the introduction of Object-Oriented Software Systems for many, by admitting up front that it is a departure from what many familiar with imperative, top-down programming are used to. These variables have names, so we can understand what object they hold. To do this, we use variables, which are references to parts of the memory. But we can’t access them directly we need a way to refer to that particular memory address, where an object is. In programming, we store objects in memory. It’s the same variable, but it refers to a different object. When this happens, the same ‘I’ll walk to the dog’ sentence will mean a different thing. But unfortunately, dogs have a shorter lifespan than humans do, which means that the dog can die, and the family can have a new dog. For example, when a family has a dog, and someone says, ‘I’ll walk the dog,’ everyone knows which dog she means. When we talk about a dog, we put its reference in the middle of the sentence. We reference or point to a specific dog by its name. Nevertheless, dogs answer to their names. Also, they can have numerous names, for example, nicknames. To avoid confusion, we name them and call them by their names. Sometimes we want to specify which object we’re talking about. For example, in Java, we control these with access modifiers. In programming, an object’s fields and methods can be independently accessible by other objects. With great power comes great responsibility: ![]() It would make it possible to have too much control over the dog, which we want to avoid. The dog doesn’t want the outside world to have the power to intervene in its internal state. The dog uses a simple solution: it publishes a set of well-defined behaviors to the outside world and keeps the other details to itself. ![]() We don’t usually want to know how to pump blood through a dog’s veins and lead electricity through its nerves just to make it run. This is a good thing, as these things are too complicated for us to understand in most scenarios. We don’t have a clue about their existence or their working. In programming, we call them implementation details.įor example, we don’t see a dog’s organs because the dog’s body hides them. These details are part of the inner working of the objects. Objects can have data and behavior we don’t want to see, or we shouldn’t see. Instead, we couple the action with the data because that’s how the world works. We don’t put a standing dog in a device, which spits out a sitting dog. It makes perfect sense: we tell the dog, and it sits. In other terms, we encapsulate data and the actions which operate on them: More importantly, we wrap these seemingly unrelated concepts (data and behavior) into a single entity. As a result, all instances will have these properties and behaviors. We define both fields and methods in a class. In programming, we represent these behaviors in methods. Dogs can change their state (sit or lay), interact with other objects (fetch a ball), or their environment (make everyone smile around them by acting funny). In programming, we store theis data in fields: For example, we can look at them to see their color or ask their owner to learn their name. We don’t necessarily know the values of these properties, but we can obtain them because we know they exist.
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