Object-oriented programming language” redirects here. In OOP, computer programs are designed by making them out object oriented programming vs structured programming pdf objects that interact with one another.
Object Pascal, Java, Python etc. Object-oriented programming uses objects, but not all of the associated techniques and structures are supported directly in languages that claim to support OOP. Objects sometimes correspond to things found in the real world. For example, a graphics program may have objects such as “circle”, “square”, “menu”. An online shopping system might have objects such as “shopping cart”, “customer”, and “product”. Sometimes objects represent more abstract entities, like an object that represents an open file, or an object that provides the service of translating measurements from U.
External code can use an object by calling a specific instance method with a certain set of input parameters, read an instance variable, or write to an instance variable. A program may create many instances of the same class as it runs, which operate independently. This is an easy way for the same procedures to be used on different sets of data. New objects can be created based on already existing objects chosen as their prototype.
It is the responsibility of the object, not any external code, to select the procedural code to execute in response to a method call, typically by looking up the method at run time in a table associated with the object. Encapsulation is an object-oriented programming concept that binds together the data and functions that manipulate the data, and that keeps both safe from outside interference and misuse. Encapsulation prevents external code from being concerned with the internal workings of an object. It also encourages programmers to put all the code that is concerned with a certain set of data in the same class, which organizes it for easy comprehension by other programmers. Address class, in addition to its own instance variables like “first_name” and “position”. Object composition is used to represent “has-a” relationships: every employee has an address, so every Employee object has a place to store an Address object. This allows classes to be arranged in a hierarchy that represents “is-a-type-of” relationships.
For example, class Employee might inherit from class Person. All the data and methods available to the parent class also appear in the child class with the same names. These will also be available in class Employee, which might add the variables “position” and “salary”. This technique allows easy re-use of the same procedures and data definitions, in addition to potentially mirroring real-world relationships in an intuitive way.