What is Difference between class and object of a class?

Answer 1

A class is an abstract idea. It's that "thing" you wrote the source code for.

An object is an instance of a class.

Example:

// Integer is the class; i is the instance of class Integer

Integer i;

Answer 2

A class (public) holds objects and methods (actions that can be imported and used by other objects and classes. An object is a thing that holds behavior and attributes. For example, take the scientific group of Mammal. This would be a class. Dogs, cats, 60 Minutes cohost Morley Safer, and Wooly Mammoths are all objects inside the class Mammal.

Answer 3

A class is basically a blueprint of an object (think of a class as blueprint for a house, and an object as a particular house). A class will tell you what components are necessary to make an object.



For example, a house class might say that each house object needs to specify how many floors it has, it must have a door, it must specify how many windows, it is a specific color, and it is able to be painted different colors.

A specific house object might be defined as having 2 floors and 5 windows, and it will definitely have a door. This house will be white, but can be painted different colors.


A class basically defines what properties and functions (or methods in Java) your objects will have. This way you know that when you create an object (which is based on the object's class), you know what properties it will have and what you can do with it.

So for the house example, if you want to make sure all houses can be painted different colors, you could specify a 'changecolors()' method in your house class. Then you know that you can use the changecolors() method on any house object, because it is defined in the house class.

Answer 4

Objects are instances of classes. Like a template, a class defines the variables and methods that the object should contain. An object instantiated from a class is analogous to a house created from a blueprint.

Answer 5

There is no such thing as object inheritance. An object is an instance of a class, it doesn't inherit from the class; the class simply defines the object's type. Classes, however, can inherit from other classes, creating new classes from existing classes. Derived classes inherit the combined public and protected members of their base classes, while the base classes retain control of their private members. Although it could be said that a derived object inherits the properties of its base class, that is not strictly true. The inheritance is gained via the class that defines the object, not by the object itself.

Answer 6

Object:

Object is an entity that can be manipulated by the commands of a programming language such as values, variables , functions or data structure.

Class:

Class is a construct that is used as a blueprint to create a instance of itself - referred to as a objects.

Answer 7

Class

Defines the abstract characteristics of a thing (object), including the thing's characteristics (its attributes, fields or properties) and the thing's behaviors (the things it can do, or methods, operations or features). One might say that a class is a blueprint or factory that describes the nature of something. For example, the class Dog would consist of traits shared by all dogs, such as breed and fur color (characteristics), and the ability to bark and sit (behaviors). Classes provide modularity and structure in an object-oriented computer program. A class should typically be recognizable to a non-programmer familiar with the problem domain, meaning that the characteristics of the class should make sense in context. Also, the code for a class should be relatively self-contained (generally using encapsulation). Collectively, the properties and methods defined by a class are called members.

Object

A pattern (exemplar) of a class. The class of Dog defines all possible dogs by listing the characteristics and behaviors they can have; the object Lassie is one particular dog, with particular versions of the characteristics. A Dog has fur; Lassie has brown-and-white fur.