November 30, 2017
OOP
Object
oriented programming is a technique for developing software on the basis of
object is called
object
oriented programming.
OOP stands
for Object Oriented programming first we understand its working and
functionality then we discuss its advantages and some other theory about OOP.
Syntax of OOP
#include<"file.header"> //Header files//
class example{ //example is the class name that we created//
private:
char name;
int age; /*Public and private , These are the Access specifiers.
Detail is given in the below page.*/
public:
int data()
{
definition of the function;
}
};
Some important questions must be known before starting the OOP.
What are the data members and member functions?
These are the data of a class.If we define or declare a variable in a class, that variable is known as data member of that class.Similarly if we define a function in a class, that function is known as member function of that class.
What are the Access specifiers?
Access
specifiers are commands used for setting the access level to the data members
and member function of a class are known as access specifiers.By default
the access specifier are “Private”.There are
three types of access specifiers.·
Private
Private
|
Protected
|
Public
|
Private
data can access only within that class in which it is defined.
|
Protected
data can be access in that class in which it is defined as well as can be
access “inhered” classes or child classes.
|
Public
data can be accessed anywhere in the program or any class can be used that
type of data.
|
What is a class?
A class is a
collection of data members and member functions that are used for the
definition of objects.
In simply a
class contain the properties of the objects.
What is an object?
An object is
a name that can access or explore the data of a class.
Suppose we
make a class of Employees and ali can be the object of Employees class.
Declaring
of objects for accessing member functions:
- ClassName ObjectName;
- objectName.functionName
First write
the class name then writes the object name for accessing a function oop use dot
operator between the object and the function.
employees
ali;
ali.dispSalary();
Here
dispSalary() is the member function of class employees.
In program where we can define a class?
- We can define a class in three places.
- · Before the main function.
- · After the main function.
- · In a separate file. (Then include that file with the header files)
In which ways we can define a function present in class?
We can
define a function declare in the class at two places.
Within the class.
Declare the
function and simultaneously define that function within that class.
Outside the class.
Declare a
function and define it outside the class using Scope resolution operator (::) J
That
function must be public in the class.
In which ways we can declare an object?
Generally we
declare the object in the main function but we can declare it in two ways.
- In main function.
- After the ending of the class and before the semicolon.
class example{
data member;
member function();
} object ;
How we can use an object for accessing the member functions and Data members of a class?
ClassName objectName;objectName.functionName;In this way we can access a function define in the class.
// program input a number and display that number//
#include<iostream>
#include<conio.h>
using
namespace std;
class inputDispValues
{
private:
int
num;
public:
int inputValue(){
cout<<"Enter a number \n";
cin>>num;
}
void outputValue()
{
cout<<"You entered
\n"<<num<<endl;
}
};
int main()
{
inputDispValues obj;
obj.inputValue();
obj.outputValue();
getch();
return 0;
}
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