What is a class in programming?

Answer 1

class is summation of data member and data types(basically known as instance variable of a class). making a class is basically an encapsulation under various access specifiers on which its object accessibility depends. these data functions can be accessed inside or outside the class with the help of object(class variable) of a class. an object defined in another class(i.e. outside the original class) can access its own class members which r not declared under private mode but can access public members and it is derived then can also access protected data members or data types also.

Answer 2

A class is the principle method of data encapsulation and structured programming in a program. The class, just like in C++ and many other Object Oriented programming languages, contains its own constructor, encapsulated variables, and encapsulated methods/functions. In Java, all classes are descended from the Object class. Classes can extend other classes to inherit their public or protected member variables and methods. Java classes are expressed by the keywords "public class" in the source file, and each class is compiled into a .class Java bytecode file for the JVM to read.

Answer 3

You define a class by providing a declaration of the class (the prototype), and an implementation of the class (the definition itself).

// Declaration of a class:

class MyClass

{

public:

MyClass():m_num(0){} // inline implementation of the default constructor

MyClass(const MyClass & myClass);

private:

int m_num;

};

// External implementation of the copy constructor:

MyClass:MyClass(const MyClass & myClass ):m_num( myClass.m_num){}

Usually the definition is placed in a header file (MyClass.h) while the declaration is placed in a source file (MyClass.cpp) which must include the header file. The main reason for this is that if you later decide to distribute your class as a library, the implementation is completely hidden from consumers -- they can only see the code contained in the header. Other sources that use your class need only include the header file (the defintiion) to make use of the class.

The only exception is when declaring template classes -- the declaration and implementation must be contained in the same file.

Answer 4

A class defined within another class is known as in inner class.

Answer 5

class is collection of object because of in java everything is considered as object, thats why we can say class is collection of objects.