Java what is a class

For example, if I created a class called Print. What does Print. When you write. Class object that represents information about given class. For example, if your class is Print , then Print. It is the same object that is returned by the getClass method of any direct instance of Print.

Just to clarify, this '. Object in OOP theory. This '. Generally you can gather meta data for your class such as the full qualified class name, list of constants, list of public fields, etc, etc. Normally you don't plan on using Reflection right away when you start building your project.

It's something that you know you need after trying to manage already working code. Many times you need it to manage multiple instances of your program. Maybe you want to identify each particular 'clone' to determine if something is already defined, or count the number of functions, or just simply log the details of a particular instance of your class.

If an instance of an object is available, then the simplest way to get its Class is to invoke Object. If the type is available but there is no instance then it is possible to obtain a Class by appending. This is also the easiest way to obtain the Class for a primitive type. See: docs. If there is no instance available then. Since, there is no instance of primitive data type, we have to use.

Suppose you have a a class named "myPackage. Assuming that is in classpath, the following statements are equivalent. Please note that the class "Class" does not have a public constructor. So you cannot instantiate "Class" instances with "new" operator. I think the key here is understanding the difference between a Class and an Object. An Object is an instance of a Class. But in a fully object-oriented language, a Class is also an Object. So calling. A class literal is an expression consisting of the name of a class, interface, array, or primitive type, or the pseudo-type void, followed by a '.

One of the changes in JDK 5. Class is generic, java. Stack Overflow for Teams — Collaborate and share knowledge with a private group. When you send a message to an object, you are asking the object to invoke or execute one of its methods as defined in the class. From a programming point of view, an object in OOPS can include a data structure, a variable, or a function.

It has a memory location allocated. Java Objects are designed as class hierarchies. A Class in object oriented programming is a blueprint or prototype that defines the variables and the methods functions common to all Java Objects of a certain kind.

An object in OOPS is a specimen of a class. Software objects are often used to model real-world objects you find in everyday life. You will need various information about the dogs like different breeds of the dogs, the age, size, etc. Some of the differences you might have listed out maybe breed, age, size, color, etc.

If you think for a minute, these differences are also some common characteristics shared by these dogs. These characteristics breed, age, size, color can form a data members for your object. Next, list out the common behaviors of these dogs like sleep, sit, eat, etc.

So these will be the actions of our software objects. In object-oriented terms, we say that your bicycle is an instance of the class of objects known as bicycles. A class is the blueprint from which individual objects are created. The following Bicycle class is one possible implementation of a bicycle:. The syntax of the Java programming language will look new to you, but the design of this class is based on the previous discussion of bicycle objects.

The fields cadence , speed , and gear represent the object's state, and the methods changeCadence , changeGear , speedUp etc. You may have noticed that the Bicycle class does not contain a main method.