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C++ Control Statements

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C++ Functions

C++ Call by Value C++ Call by Reference C++ Recursion Function C++ Inline function C++ Friend function

C++ Arrays

Single dimension array Two dimension array

C++ Strings

C++ Strings

C++ Inheritance

C++ Inheritance Single level Inheritance Multilevel Inheritance Multiple Inheritance Hierarchical Inheritance Hybrid Inheritance

C++ Polymorphism

C++ Polymorphism C++ Overloading C++ Overriding C++ Virtual Function

C++ Pointers

C++ Pointers C++ this pointer

C++ Exception Handling

C++ Exception Handling

C++ Constructors

C++ Constructors Default Constructor Parameterize Constructor Copy constructor Constructor Overloading Destructor

C++ File Handling

C++ File Handling C++ Writing to file C++ Reading file C++ Close file

Miscellaneous

C Vs C++ C++ Comments C++ Data Abstraction C++ Identifier C++ Memory Management C++ Storage Classes C++ Void Pointer C++ Array To Function C++ Expressions C++ Features C++ Interfaces C++ Encapsulation std::min in C++ External merge sort in C++ Remove duplicates from sorted array in C++ Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++ C++ References C++ Friend Functions C++ Mutable keyword Unary Operators in C++ Initialize Array of objects with parameterized constructors in C++ Differences between #define & const in C/C++ C++ Program to Implement Shell Sort C++ Program to Implement Merge Sort Storage Classes in C Vector resize() in C++ Passing by Reference Vs. Passing by the pointer in C++ Free vs delete() in C++ goto statement in C and C++ C++ program to read string using cin.getline() C++ String Concatenation Heap Sort in C++ Swap numbers in C++ Input Iterators in C++ Fibonacci Series in C++ C ++ Program: Alphabet Triangle and Number Triangle C++ Program: Matrix Multiplication C++ Program to Print Fibonacci Triangle Stack in C++ Maps in C++ Queue in C++ C++ Bitset C++ Algorithms Priority Queue in C++ C++ Multimap C++ Deque Function Pointer in C++ Sizeof() Operators in C++ C++ array of Pointers free() Vs delete in C Timsort Implementation Using C++ CPP Templates C++ Aggregation C++ Enumeration C++ Math Functions C++ Object Class C++ Queue Initialize Vector in C++ Vector in C++ C++ STL Components Function overloading in C++ C++ Maximum Index Problem C++ find missing in the second array C++ Program to find the product array puzzle C++ Program To Find Largest Subarray With 0 Sum C++ Program To Move All Zeros To The End Of The Array C++ Program to find the element that occurs once C++ Program to find the largest number formed from an array Constructor Vs Destructor C++ Namespaces C++ OOPs Concept C++ Static C++ Structs C++ Try-Catch C++ User Defined Exceptions C++ Virtual Destructor C++ vs C# Malloc() and new in C++ Palindrome Number Program in C++ Snake Code in C++ Splitting a string in C++ Structure Vs Class in C++ Virtual Function Vs Pure Virtual Function C++ Bidirectional Iterators C++ Forward Iterators C++ Iterators C++ Output Iterators C++ Range-based For Loop Converting string into integer in C++ LCM Program in C++ Type conversion in C++ Add two numbers using the function in C++ Advantage and disadvantage friend function C++ Armstrong Number Program in C++ ATM machine program in C++ using functions Binary to Decimal in C++ Bit Manipulation in C++ C++ Constructor C++ Dijkstra Algorithm Using the Priority Queue C++ int into String C++ Signal Handling Decimal to Binary in C++ Decimal to Hexadecimal in C++ Decimal to Octal in C++ Factorial Program in C++ Function in C++ Hexadecimal to Decimal in C++ Octal to Decimal in C++ Reverse a Number in C++ Structure Vs Class in C++ C++ Forward Iterators C++ Output Iterators C++ Prime number program Char Array to String in C++ Constructor Overloading in C++ Default arguments in C++ Different Ways to Compare Strings in C++ Dynamic Binding in C++ Program to convert infix to postfix expression in C++ SET Data Structure in C++ Upcasting and Downcasting in C++ Reverse an Array in C++ Fast Input and Output in C++ Delete Operator in C++ Copy elision in C++ C++ Date and Time C++ Bitwise XOR Operator Array of sets in C++ Binary Operator Overloading in C++ Binary Search in C++ Implementing the sets without C++ STL containers Scope Resolution Operator in C++ Smart pointers in C++ Types of polymorphism in C++ Exception Handling in C++ vs Java Const Keyword in C++ Type Casting in C++ Static keyword in C++ vs Java Inheritance in C++ vs Java How to concatenate two strings in C++ Programs to Print Pyramid Patterns in C++ swap() function in C++ Structure of C++ Program Stringstream in C++ and its applications rand() and srand() in C / C++ C++ Ternary Operator C++ Scope of Variables While Loop Examples in C++ Star pattern in C++ using For Loops For Loop Examples in C++ Do-While Loop Examples in C++ Top 5 IDEs for C++ That You Should Try Once Assertions in C/C++ C++ Convert Int to String Continue in C++ While loop Diamond Pattern in C++ using For Loop How to Reverse a String in C++ using Do-While Loop How to Reverse a String in C++ using For Loop How to Reverse a String in C++ using While Loop Infinite loop in C++ Loops in C++ Returning Multiple Values from a Function using Tuple and Pair in C++ wcscpy(), wcslen(), wcscmp() Functions in C++ Auto keyword in C++ C++ 11 vs C++ 14 vs C++ 17 C++ STL (Standard Template Library) Differences Between C Structures and C++ Structures Divide by Zero Exception in C++ Dynamic Constructor in C++ Dynamic Memory Allocation in C++ Find the Size of Array in C/C++ without using sizeof() function Floating Point Operations and Associativity in C, C++ and Java Hello World Program in C++ How to create a table in C++ How to Setup Environment for C++ Programming on Mac Implementation of a Falling Matrix in C++ Message Passing in C++ Pointer to Object in C++ Templates in C++ vs Generics in Java Ways to Copy a Vector in C++ What does Buffer Flush mean in C++ sort() function in C++ Structure Sorting (By Multiple Rules) in C++ Similarities between C++ and Java std::distance in C++ Array program in C++ C++ Tricks for Competitive Programming Desired Capabilities in Selenium Web Driver in C++ Socket Programming in C++ Template Specialization in C++ Classes and Objects in C++ Convex hull Algorithm in C++ DES in C++ C++ vardiac() function Difference between Two Sets in C++ Difference between Exit and Return Structured Binding in C++ Differences between Local and Global Variable Bitwise Operator vs Logical Operator Difference between OOP and POP in C++ Fork in C++ Functors in C++ How to call a void function in C++ How to create a directory or folder in C/C++ How to create a library in C++ How to create a stack in C++ How to create the Processes with Fork in C++ How to Handle Divide by Zero Exception in C++ Lambda Expression in C++ Pattern programs in C++ Roadmap to C++ Programming Substring in C++ Virtual base class in C++ Bits stdc++.h in C++ Top 14 Best Free C++ IDE (Editor & Compiler) for Windows in 2022 Bitmasking in C++ Auto Keyword in C++ Features of OOPS in C++ Hospital Management Project in C++ How to Declare Unordered Sets in C++ How to Sort an Array in C++ Include Guards in C++ Iostream in C++ Method overriding in C++ How to run program in turbo c++ How to Use Getline in C++ Leap Year Program in C++ Naming Convention in C++ New Operator in C++ Nullptr in C++ Object Slicing in C++ Principles of Object-Oriented Programming in C++ Processing strings using std string stream in C++ Pure Virtual Function in C++ With Example Program Random Number Generator in C++ Singleton Design Pattern in C++ Size_t Data Type in C++ Skyline Problem in C++ System() function in C++ Web Development in C++ Data Hiding in C++ Difference between exit() and _Exit() in C++ Hashing in C++ Object in C++ Sum of all Elements between k1’th and k2’th Smallest Elements Virtual class in C++ Vector Size in C++ Top best IDEs for C/C++ Developers in 2022 Tensorflow in C++ Sliding Window Technique in C++ Reverse String Word-Wise in C++ Returning a Function Pointer from a Function in C/C++ RTTI in C++ Pthreads or POSIX Threads in C++ Reserved Keywords in C++ Passing a Vector to a function in C++ 10 Best C and C++ Books for Beginners & Advanced Programmers Add two numbers represented by two arrays in C++ Array of Object in C++ C++ Program For FCFS Containership in C++ Counting Frequencies of Array Elements in C++ Decltype type Specifier in C++ Dynamic _Cast in C++ Difference between int main() and int main(void) in C/C++ Depth First Search Program to Traverse a Graph in C++ Features and Use Of Pointers in C/C++ Fread Function in C++ Programming Fscanf Function in The C++ Functions in C++ With Types and Examples Gmtime Function in C/C++ How is Multiset Implemented in C++ How to Build a Program in C++ How to Declare a 2d Array Dynamically in C++ inheritance Program in C++ int Max and int Min in C/C++ is It Fine to Write Void Main Or Main in C/C++ How to create a button in C++ abs() function in C++ Compile Time Polymorphism in C++ Division in C++ Factorial of a Number in C++ using while Loop Multiset in C++ 4 Pillars of OOPs Approach in C++ Backtracking Time Complexity in C++ C++ Global Variable C++ Pipe Tutorial Observer Design Pattern in C++ Private Inheritance in C++ Pthread in C++ Parameters SDL library in C++ with Examples Pointers in C++ Abstract Factory Design Pattern in C++ Ascending order in C++ How the value is passed in C++ Call by Pointer in C++ Constexpr in C++ Deadlock in C++ Design 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How to use the string find() in C++ Dynamic Casting in C++ 2D Vector Initialization in C++ C++ GUI Visual Studio C++ IPC C++ Macro Function Example C++ Permutation Overloading Stream Insertion in C++ Overloading array Index operator in C++ Operators that cannot be overloaded in C++ Operator overloading in C++ isprint() function in c++ Is_trivial function in C++ Is assignment operator Inherited in C++ div() function in C++ Default Assignment Operator and References in C++ Copy Constructor vs Assignment Operator in C++ Conversion Operator in C++ Array sum in C++ STL C++ Define Macro C++ Design C++ Factory Pattern TCP Client Server Example in C++ Convert String to Uppercase in C++ exit() and _Exit() in C and C++ Initializer list in C++ Iterator invalidation in C++ Lower bound in C++ Modulus of Two float numbers or double number Pass by value in C++ Set insert function in C++ Std partition_point in C++ Unary Operator Overloading in C++ Using Default Arguments with Virtual Functions Virtual Functions and Runtime Polymorphism What is endl in C++ What is Unary Operator Overloading in C++ Which operators cannot be overloaded in C++ C++ Program to Divide the String Into N equal Parts Gray Code to Binary Code in C++ How to get the value of pi in C++ Multimap value_comp() function in C++ Vector of Vectors in C++ Naïve Bayes Algorithm in C++ Minimum Cost Path Problem in C++ 10 C++ Programming Tricks You Should Know btowc() function in C++ forward_list::cend() in C++ Unordered_multimap max_load_factor() function in C++ Cpp_int in c++ Dynamic Objects in C++ FLOCK() FUNCTION IN C++ Generate Random Double Numbers in C++ How to Assign Infinity to a Number in C++ Jump statements in C++ Multipath inheritance in C++ Out of Range Exception in C++ Size of Class in C++ Size of string in C++ std::binary_negate in c++ Thread_local in C++ Tokenizing a String in C++ Ancestors of a Node in Binary Search Tree C++ program for Double to String Conversion C++ Program to Demonstrate Use of Formatting Flags on Float Output Clamp in C++ K-Dimensional Tree in C++ Mutable Lambda in C++ Power Set in C++ Program to Find Sum of Geometric Progression Std::Back_inserter in C++ Strpbrk() function in C++ Size of int in C++ TYPES OF MANIPULATORS IN C++ Double colon in C++ How to sort vector in C++ How to use Setprecision in C++ How to write a Vector in C++ Insertion in Splay Tree in C++ Merge Sort Algorithm in C++ Printing a Character using ASCII value in C++ Regex in C++ Size of Data Types in C++ Sqrtf() function in C++ Static Casting in C++ Using Range in Switch Case in C++ wcstoimax() and wcstoumax() function in C++ What is float in C++ What is the Diamond Problem in C++ Best way to learn C++ ios setstate() function in C++ Nested Namespace in C++ Single Inheritance in C++ std::fixed, std::scientific, std::hexfloat, std::defaultfloat in C++ StringStream in C++ for Decimal to Hexadecimal and back The OFFSETOF() macro in C++ Difference between std::next and std::advance in C++ Hiding of all overloaded methods with same name in base class in C++ C++ program to concatenate two strings using operator overloading Difference between array::fill() and array::swap() in C++ Difference between Friend Function and Virtual Function in C++ Semaphores in C++ Seekg in C++ UDP server- client implementattion in C++ What is long long in C++ CSV file management using C++ Toggle bits of a number except first and last bits in C++ Trailing Return Type C++ 11 Binary search implementation in C++ Different Versions of C++ What is Cascading in C++ Background Colour in C++ BOOL DATATYPE IN C++ BIT VECTORS IN C++ Literals in C++ Application of pointer in C++ Index with minimum sum of prefix and suffix sums in an array in C++ Maximum sum Bi-tonic sub-sequence in C++ std::optional in C++ C/C++ program for triangular matchstick number COUT COMMAND IN C++ LANGUAGE Adjacency matrix program in C++ language Difference between Null String and Empty String in C++ Character data type in c++ Constructors in Inheritance C++ Comma Operator Overloading in C++ Structure and Class in C++ Template Definition in C++ Tree Data Structure in C++ Typename in C++ C++ program to implement the bin packing algorithm How to merge multiple std::sets into a single std::set in C++? Stack Clear C++ C++ Friend Class Seekg in C++ Semaphores in C++ C++ Exceptions Difference Between C and C++ Double-linked list program in C++ Color Code in C++ CRC Program in C++ Anti-Clockwise spiral traversal of a binary tree in C++ Advantages of OOP in C++ Cryptarithmetic Puzzle in C++ Angular sweep algorithm in C++

4 Pillars of OOPs

OOPs

OOPS means Object Oriented Programming System Structure. Object oriented Programming is defined as an approach that provides a way of modularizing programs by creating partitioned memory area for both data and functions that can be used as templates for creating copies of such modules on demand. Some features of OOPs are:

  • OOPS is a Paradigm (Methodology / Way of programming).
  • C++, Java, Python, and C# support OOPS.
  • OOPS allows users to create a class and use them throughout the program by creating an object of the class.
  • OOPS provide protection or security for the program.
  • Every unity game programming supports OOPS.

Pillars of OOPS

There are mainly 4 pillars or concepts of OOPS:

  1. Abstraction
  2. Inheritance
  3. Encapsulation
  4. Polymorphism
4 Pillars of OOPs

1. Abstraction

Data Abstraction is a purposeful process of hiding confidential information from the outside world.

Data abstraction is a way of hiding internal details /information in a program from the user and the outside world. It provides data that the public class can access.

Abstraction made it easy for users to interact with the programming language by hiding irrelevant information.

Benefits of Data Abstraction

Data abstraction provides important advantages -

  • Class data are protected from unwanted user-level errors.
  • It becomes easier to operate with the help of data abstraction.
  • Helps to improve the security level of an application or a program, as
  • only basic information is visible to the user.
  • Reduction in low-level code.
  • It reduces the complexity of a program for the user. It becomes
  • easy to read and understand by the user.
  • It avoids duplication of code and thus increases the reusability.
  • In big projects, Abstraction is very useful as portioning across the program provides structure, and error finding becomes easy.

Ways to implement Abstraction in C++

There are two ways to achieve Abstraction in C++:

1. Abstraction using classes

2. Abstraction using header files.

1. Abstraction using classes

An abstraction can be done through classes. A class has some specifiers that can control which data or function is to be visible to the user and which is not.

Example-

#include <iostream>
using namespace std;
class sample {
    public:
        int x, y, z;
	public:
		void put() {
		   cout<< "enter three values:" << endl;
		   cin>>x>>y >> z;
		}
	private:
		void display() {
		    cout<< "sum of x y z is: "<<endl;
			cout<< x +y+ z;
	} };
int main() {
      sample s1;
      s1.put();
      s1.display();
      return 0;
}

Explanation-If we run this program, then private member functions will not be accessible by the compiler so it will generate an error.

OUTPUT

4 Pillars of OOPs

Another example of declaring all the member functions in public modifiers:

#include<iostream >
using namespace std;
 class sample {
            private:
			int x, y, z;
  			public:
				void put() {
					cout<< "enter three values" <<endl;
					cin>> x>> y>>  z;
				}
			public:
					void display() {
						cout<<"sum of x y z is"<< endl;
						cout<< x+ y+ z;
					} 
			};
int main() {
	sample s1;
	s1.put();
	s1.display();
	return 0;
}

Explanation --If you execute this program, all the class member functions and data members will be accessible, so this will generate the following output:

OUTPUT

4 Pillars of OOPs

2. Abstraction in Header files

Abstraction can be achieved through header files in C++. For example, in <math.h> header file in C++, sqrt() function is available to calculate the square root of any number without knowing the actual algorithm behind it. So, the header file hides the implementation details from the user.

Example-

#include<iostream>
#include<math.h>
using namespace std;
int main()
{
cout<< "Square root of 144 is ";
//header file used to find the square root
cout<< sqrt(144) <<endl;
return 0;
}

OUTPUT

4 Pillars of OOPs

Inheritance

Inheritance is a concept of OOPS in which one class inherits the property of another class. When one class accesses the property or characteristics of another class, it is known as inheritance.

4 Pillars of OOPs

Derived class- also called the child class. It is the class that inherits from another class.

Base class- also called parent or superclass. It is a class that is inherited.

Syntax:

       Class <derived class name> : access specifier < base class name>
{
	//statements..;
}

Access specifier/ modes in inheritance

There are 3 access specifiers in inheritance:

  1. Public mode
    If we derive a base class from a public modifier base class, then the public member of the base class will become public in the derived class, and protected members of the base class will become protected in the derived class.
  2. Protected mode
    If we derive a subclass from a protected base class, then both the public member and protected member will become protected in the derived class.
  3. Private mode
    If we derive a subclass from the private base class, then both public and protected members will become private in the derived class.

Advantages of inheritance

1. Reduce code size.

2. Provides better code reusability.

3. Improves code readability as code is divided into classes.

4. Different clients can use member functions of their want and add more by inheritance.

5. No duplication of code.

Types of inheritance

There are 5 types of inheritance, and they are:

  1. Single inheritance
  2. Multi-level inheritance
  3. Multiple inheritance
  4. Hybrid inheritance
  5. Hierarchical inheritance

 i. Single inheritance

The inheritance in which only one base class and one parent class is called single inheritance.

Code example-

#include<iostream>							
using namespace std;
class A {
	public:
    	void func() {								
		 cout<< "Inherited" << endl;
	}
};
class B:public A {					
	};			
int main() {
	B ob;
	ob.func();
	return 0;
}

OUTPUT

4 Pillars of OOPs

ii. Multi-level inheritance

The inheritance in which another class can again derive a derived class is called multi-level inheritance.

Code example-

#include<iostream>
using namespace std;
class A {
	public:
	void Afunc() {
		cout<<"Function A"<< endl;
	}
};
class B : public A {
	public:									
	void Bfunc() {
		cout<<"\nFunction B";						
	} };
class C : public B {
};
int main() {
	C obj;
	obj.Afunc();
	obj.Bfunc();
	return 0;
}

OUTPUT

4 Pillars of OOPs

iii. Multiple Inheritance

The inheritance in which a parent has more than one base or child class is called multiple inheritance.

Code example-

#include<iostream>
using namespace std;
class A {
	public:
	void Afunc() {
		cout<< " Function A" << endl;
	}
};
class B {
	public:									
	void Bfunc() {
		cout<<" \n Function B ";						
	} };
class C : public A , public B {
};
int main() {
	C obj;
	obj.Afunc();
	obj.Bfunc();
	return 0;
}

OUTPUT

4 Pillars of OOPs

iv. Hierarchal  inheritance

 This type of inheritance has a tree-like structure as every class act as a parent class for another class.

Code example-

#include <iostream> 
using namespace std; 
//hierarchical inheritance example 


class Shape    // shape class -> base class 
{
public: 
int x,y; 
void get_data(int n,int m) { 
x= n; 
y = m; 
} 
};
class Rectangle : public Shape  {	// inherit Shape class 
public: 
int area_rect() { 
int area = x*y; 
return area; 
} 
};
class Triangle : public Shape 		// inherit Shape class 
{
public: 
int triangle_area() { 
float area = 0.5*x*y; 
return area; 
} 
};
class Square : public Shape	 // inherit Shape class 
{
public: 
int square_area() { 
float area = 4*x; 
return area; 
} 
};
int main() 
{
 Rectangle r; 
Triangle t; 
Square s; 
int length,breadth,base,height,side; 
//area of a Rectanglest 
cout << "Enter the length and breadth of a rectangle: "; 
cin>>length>>breadth; 
r.get_data(length,breadth); 
int rect_area = r.area_rect(); 
cout << "Area of the rectangle = " <<rect_area<< endl; 
//area of a triangle 
cout << "Enter the base and height of the triangle: "; 
cin>>base>>height; 
t.get_data(base,height); 
float tri_area = t.triangle_area(); 
cout <<"Area of the triangle = " << tri_area<<endl; 
//area of a Square 
cout << "Enter the length of one side of the square: "; 
cin>>side; 
s.get_data(side,side); 
int sq_area = s.square_area();
cout <<"Area of the square = " << sq_area<<endl; 
return 0; 
}

OUTPUT

4 Pillars of OOPs

V. Hybrid inheritance

This is a combination of more than one inheritance. Hybrid inheritance can be a combination of two or more types of inheritance.

Code example-

#include <iostream> 
#include <string> 
using namespace std; 
//Hybrid inheritance = multilevel + multilp
class student 	//First base Class
{  
int id; 
string name; 
public: 
void getstudent(){
cout << "Enter student Id and student name:\n";
cin >> id >> name; 
} 
};
class marks: public student{
public:		 //derived from studentprotected: 
int marks_math,marks_phy,marks_chem; 
void getmarks(){
cout << "Enter 3 subject marks:"; 
cin >>marks_math>>marks_phy>>marks_chem; 
} 
};
class sports{ 
protected: 
int spmarks; 
public: 
void getsports(){
cout << "Enter sports marks:";cin >> spmarks; 
} 
};
class result : public marks, public sports	//Derived class by multiple inheritance
{
int total_marks; 
float avg_marks; 
public : 
void display(){ 
total_marks=marks_math+marks_phy+marks_chem; 
avg_marks=total_marks/3.0; 
cout << "Total marks =" << total_marks << endl;
cout << "Average marks =" << avg_marks << endl; 
cout << "Average + Sports marks =" <<avg_marks + spmarks; 
} 
};
int main(){ 
result res;//object// 
res.getstudent(); 
res.getmarks(); 
res.getsports(); 
res.display(); 
return 0; 
}

OUTPUT

4 Pillars of OOPs

Explanation--Here we have four classes i.e., Student, Marks, Sports, and Result. Marks are derived from the student class. The class Result derives from Marks and Sports as we calculate the result from the subject marks as well as sports marks. The output is generated by creating an object of class Result that has acquired the properties of all the three classes.

Encapsulation

Encapsulation can be defined as wrapping up data and functions together into a single unit.

Wrapping them up into a single unit means combining data member and member functions into a single class. It helps with data hiding.

Consider a real-life-based example-

Different departments in a company have different roles and contributions to the company. Suppose a company has production, sales, and IT departments. The production department handles all records of how much production is required to meet. Similarly, the sales department records all the sales. For more reason, the production department head wants the sales record of the month. In this case, he cannot directly access the sales department records. He must first request some sales department official to get the data.

This is what encapsulation does. To access a member function from the class, we need an object to call it. The object is made in the main function.

For example-

#include<iostream>
using namespace std;
class ball {
	private:
	    float area;
	public:
		void setarea (int radius ) {
			area= 3.14 * radius * radius;
		}
	float getarea() {
		return area;
	}
};
int main() {
	ball b1;
	b1.setarea(7);
	cout<<"Area of ball is ";
	cout<< b1.getarea() ;
 	return 0;
}

OUTPUT

4 Pillars of OOPs

NOTE: Only class member functions can access private data members (area) in this code. The member functions and data members are combined together so that they can manipulate each other. This is called encapsulation.

Access specifier in encapsulation

  1. in public scope, other classes and functions can access the data members and member functions.
  2. - in private scope, only the member functions inside the class have access to class members. Functions outside the class cannot access them.
  3. - similar to private scope, we cannot access member function from the outside class, but they can be accessed from derived class.

Difference between Abstraction and Encapsulation

EncapsulationAbstraction
Encapsulation combines data and functions together into a single unit.In Abstraction, the unwanted information is kept hidden.
It helps in hiding data.It helps in hiding the implementation of code or program.
It can be implemented using access modifiers.It can be implemented using abstract class as well as access modifiers.
In this, problems are solved at the implementation levelIn this, problems are solved at the design level.

Polymorphism

Polymorphism is made up of two words:

  • Poly- many
  • Morphism-forms

The meaning of polymorphism is the same object has different behavior. It means having different functions have the same name.

Types of polymorphism

4 Pillars of OOPs

   There are two types of polymorphism:

  1. Compile time polymorphism
  2. Run time polymorphism.

Compile time polymorphism

The function is called at the time of compiling the program. It is called compile-time polymorphism.

Also called static binding.

Compile time polymorphism has two types- function overloading and operator overloading.

i. Function overloading

In functionoverloading, more than one function has the same name with different arguments passed inside them. The same function can perform many tasks with different arguments. The function is called at the time of compilation, so it is called compile time polymorphism.

Example-

#include<iostream>
using namespace std;
class demo {
	public:
		void printresult( int i) {
			cout<< "print integer result: "<< i<<endl;
	}
		void printresult(double f) {
			cout<< "print float result: "<< f<<endl;
     }
		void printresult (string c) {
			cout<< "print string result: "<< c<<endl;
    }
};
int main()
{
	demo show;
	show.printresult(5);
	show.printresult(400.363);
      show.printresult("Welcome to programming");
	return 0;
}

OUTPUT

4 Pillars of OOPs

--In this program printresult() function called integer, float, and string data type with the same name but different arguments.

ii. Operator Overloading

An operator symbol (+, -,*,/) used differently is called operator overloading.

Operator overloading means assigning additional operand tasks without changing their actual functionality.

Example-

#include<iostream>
using namespace std;
class complex {
	private: int a, b;
	public:
		void getdata(int x, int y) {
			a= x;
			b= y; 
		}
		void showdata() {
			cout<< "value of a= "<< a;
			cout<< "\nvalue of b= "<< b;
		}
		complex operator +(complex obj)
		{
			complex temp;
			temp.a = a + obj.a;
			temp.b = b + obj.b;
			return temp;
		}
};
int main()
{
	complex t1, t2, t3;
	t1.getdata(1, 2);
	t2.getdata(2, 3);
	t3=t1 + t2;
 	// t3 = t1. Operator +(t2)
	t3.showdata();
	return 0;
}

OUTPUT

4 Pillars of OOPs

Run Time Polymorphism

In Runtime polymorphism, functions are called at the time of the program execution.

Run time polymorphism has two types- function overriding and virtual function.

i. Function Overriding

In function overriding, the main function is rewritten in the derived class.

Thus, the main or base function is overridden. Overriding can only be possible in a derived class. The same function has two definitions- one in the base class and another in the derived class. The compiler decides which function should call at run time, so this is called run time polymorphism.

 Example-

#include<iostream>
using namespace std;
class bank {
	public:
		float a, intr, tot_balance;
		void calc_interest( float balance)
 {
			a= balance;
			intr= a * 4/100;
			tot_balance = a + intr;
			cout<< "your interest is: "<< intr;
			cout<< "\nyour total balance is: "<< tot_balance;
		}
};
class sbi : public bank {
	float a, intr, tot_balance;
	public:
		void calc_interest(float balance) {
			a= balance;
			intr= a * 5/100;
			tot_balance = a + intr;
			cout<< "your interest is: "<< intr;
			cout<< "\nyour total balance is: "<< tot_balance;
		}
};
int main() {
	sbi obj;
	obj.calc_interest(500);
	return 0;
}

OUTPUT

4 Pillars of OOPs

ii. Virtual Function

A virtual function is a function in which the programmer determines which version of the function to use.

The function is declared in the base class with a virtual keyword, then redefined in derived classes.

Example-

#include<iostream>
using namespace std;
class demo {
	public:
		virtual void f1() {
			cout<< "base class"<< endl;
		} };
class abc: public demo {
	public:
		void f1() {
			cout<< "Derived class"<< endl;
		}
};
int main()
{
	abc a;
	demo *d= &a;
	d->f1();
	return 0;
}

OUTPUT

4 Pillars of OOPs