C++ Tutorial index

C++ Tutorial C++ History C++ installation C++ First Program C++ cin and cout C++ Data type C++ Variable C++ operator C++ Keywords C++ OOPS Concepts 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

C++ Control Statements

C++ If C++ Nested if C++ If-else C++ If-else-if C++ Switch C++ Break C++ Continue C++ Goto C++ for loop C++ While loop C++ Do while loop

C++ functions

function in C++ C++ Call by Value C++ Call by Reference C++ Recursion function C++ inline function C++ Friend function C++ Friend functions function Pointer in C++ Sizeof() Operators in C++ C++ Math functions swap() function in C++ rand() and srand() in C / C++ wcscpy(), wcslen(), wcscmp() functions in C++ sort() function in C++ C++ vardiac() function System() function in C++ Fread function in C++ Programming Fscanf function in The C++ Gmtime function in C/C++ abs() function in C++ Sleep function in C++ Stoi function in C++ String erase() in C++ String Trim in C++ isprint() function in c++ is_trivial function in C++ div() function in C++ Set insert function in C++ rint(), rintf(), rintl() in C++ String append() function in C++ String push_back() in C++ String replace() in C++ Transform function in C++ exit() and _Exit() in C and C++ Std partition_point in C++ unique() in C++ ctime() function in C++ Gets() and Puts() in C++ Hypot(), hypotf() and hypotl() in C++ Log function in C++ Nearbyint() function in C++ setf() function in C++ Fill Function in C++ Map Find Function in C++ Malloc and Calloc in C++ Operator Function in C++ cin.get() in C++ seekp() Function in C++ eof() Function in C++ Emplace Back in C++ C++ macro function C_str in C++ Clock() in C/C++ round() function in C++ scalbn() function in C++ Stable Sort function in C++ Rotate in C++ Std:: Sort_heap in C++ Std::includes() in C++ STL std::memset() function in C++ Wcscmp() function in C++ Static Member function in C++ atof() function in C++ C++ Sin() function with Example cin.ignore() function in C++ Member function in C++ Pop_front Vector in C++ Vector resize() in C++ Malloc() and new in C++ std::distance in C++ C++ Date and Time fork() in C++ std::min in C++ isprint() in C++ rdbuf() in C++ fixed() Function in C++ setw() in C++ seekg() Function in C++ isdigit() Function in C++

C++ Function Miscellaneous

Precision of floating point numbers Using these functions floor(), ceil(), trunc(), round() and setprecision() in C++ function overloading in C++ Add two numbers using the function in C++ Advantage and disadvantage friend function C++ ATM machine program in C++ using functions Returning Multiple Values from a function using Tuple and Pair in C++ Find the Size of Array in C/C++ without using sizeof() function Pure Virtual function in C++ With Example Program Returning a function Pointer from a function in C/C++ Passing a Vector to a function in C++ functions in C++ With Types and Examples C++ Macro function Example Using Default Arguments with Virtual functions Virtual functions and Runtime Polymorphism Fesetround() and Fegetround() in C++ and their application Object as function Argument in C++ Private Member function in C++ Function Overriding in C++ C++ Program for Addition of Two Numbers Using functions function Object in C++ Elements of User Defined function in C++ Inline Functions in C++ Virtual Function in C++

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

C++ Programs

Structure of C++ Program Hello World Program in C++ C++ Program to Implement Shell Sort C++ Program to Implement Merge Sort C++ program to read string using cin.getline() C ++ Program: Alphabet Triangle and Number Triangle C++ Program: Matrix Multiplication C++ Program to Print Fibonacci Triangle 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 Palindrome Number Program in C++ LCM Program in C++ Armstrong Number Program in C++ Factorial Program in C++ C++ Prime number program Program to convert infix to postfix expression in C++ Programs to Print Pyramid Patterns in C++ Array program in C++ Pattern programs in C++ Leap Year Program in C++ C++ Program for FCFS Depth First Search Program to Traverse a Graph in C++ inheritance Program in C++ Program that produces different results in C and C++ Example Program in C++ for input and Output Calculator Program using Switch in C++ Program for COPY Constructor in C++ Bank Program in C++ Anagram Program in C++

C++ Operators

Unary Operators in C++ Delete Operator in C++ C++ Bitwise XOR Operator Binary Operator Overloading in C++ Scope Resolution Operator in C++ C++ Ternary Operator New Operator in C++ Overloading array index operator in C++ Operator overloading in C++ Operators that cannot be overloaded in C++ Default Assignment Operator and References in C++ Conversion Operator in C++ Unary Operator Overloading in C++ Benefits of Operator Overloading in C++ Assignment Operator Overloading in C++ New and Delete Operator in C++ Insertion Operator in C++ Increment Operator in C++ Bitwise Operator in C++

C++ Examples

C++ Programming Examples While Loop Examples in C++ for Loop Examples in C++ Do-While Loop Examples in C++ SDL library in C++ with Examples C++ tcp client server example C++ tcp server example TCP Client Server Example in C++ Example of Parameterized Constructor in C++ Example of User Defined Data Type in C++

C++ Differences

C Vs C++ free() vs delete() in C++ Constructor Vs Destructor Passing by Reference Vs. Passing by the pointer in C++ C++ vs C# Structure Vs Class in C++ Virtual function Vs Pure Virtual function Structure Vs Class in C++ Exception Handling in C++ vs Java Static keyword in C++ vs Java inheritance in C++ vs Java C++ 11 vs C++ 14 vs C++ 17 Templates in C++ vs Generics in Java Bitwise Operator vs Logical Operator Type difference of Character literals in C VS C++ Copy Constructor vs Assignment Operator in C++ Map vs unordered_map in C++ Differences between #define & const in C/C++ Differences Between C Structures and C++ Structures Difference between Two Sets in C++ Difference between Exit and Return Differences between Local and Global Variable Difference between OOP and POP in C++ Difference between exit() and _Exit() in C++ Difference between int main() and int main(void) in C/C++ Difference Between Overloading and Overriding in C++ std::set_symmetric_difference in C++ Difference between Private and Protected in C++ Difference Between Encapsulation and Abstraction in C++ Difference between Template and Macro in C++ Difference between Abstraction and Interface in C++ Differences Between C++ and Javascript Difference between POP and OOP in C++

How To

How to concatenate two strings in C++ 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 How to create a table in C++ How to Setup Environment for C++ Programming on Mac 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++ How to Declare Unordered Sets in C++ How to Sort an Array in C++ How to run program in turbo c++ How to Use Getline in C++ How is Multiset Implemented in C++ How to Build a Program in C++ How to Declare a 2d Array Dynamically in C++ How to create a button in C++ How the value is passed in C++ How to calculate size of string in C++ How to convert binary string to int in C++ How to convert string to float in C++ How to remove space from string in C++ How to use pair in C++ How to use the string find() in C++ How to Remove an Element From an Array in C++ How to Take Space Separated input in C++ How to Copy in Turbo C++ How to Use Pow in C++ How to Use Set in C++ How to Create Singleton Class in C++ How to Allocate Memory Dynamically in C++ How to Close Turbo C++ in Windows 10 How to Use Modulus in C++

C++ Questions

What does Buffer Flush mean in C++ What is endl in C++ What is Unary Operator Overloading in C++ Which operators cannot be overloaded in C++ What is Static Member function in C++ What is This Pointer in C++ What is Upcasting in C++ What Kind of Exceptions Are Available in C++ What is Memory Allocation for Objects in C++ What is a Linked List in C++ is assignment operator inherited in C++ When should we write own Assignment operator in C++ What is an Object in C++ What is Copy Constructor in C++ What is a Static Member Function in C++

C++ Interview Questions

Advanced C++ interview Questions Oops Interview Questions in C++

Miscellaneous

External merge sort in C++ Remove duplicates from sorted array in C++ C++ References C++ Mutable keyword initialize Array of objects with parameterized constructors in C++ Storage Classes in C goto statement in C and C++ C++ String Concatenation Heap Sort in C++ Swap numbers in C++ input Iterators in C++ Fibonacci Series in C++ Stack in C++ Maps in C++ Queue in C++ C++ Bitset C++ Algorithms Priority Queue in C++ C++ Multimap C++ Deque C++ array of Pointers Timsort Implementation Using C++ CPP Templates C++ Aggregation C++ Enumeration C++ Object Class C++ Queue initialize Vector in C++ Vector in C++ C++ STL Components C++ Maximum index Problem C++ find missing in the second array C++ Namespaces C++ OOPs Concept C++ Static C++ Structs C++ Try-Catch C++ User Defined Exceptions C++ Virtual Destructor Snake Code in C++ Splitting a string in C++ C++ Bidirectional Iterators C++ forward Iterators C++ Iterators C++ Output Iterators C++ Range-based for Loop Converting string into integer in C++ Type conversion in C++ 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++ Hexadecimal to Decimal in C++ Octal to Decimal in C++ Reverse a Number in C++ C++ forward Iterators C++ Output Iterators 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++ SET Data Structure in C++ Upcasting and Downcasting in C++ Reverse an Array in C++ Fast input and Output in C++ Copy elision in C++ Array of sets in C++ Binary Search in C++ Implementing the sets without C++ STL containers Smart pointers in C++ Types of polymorphism in C++ Const Keyword in C++ Type Casting in C++ Stringstream in C++ and its applications C++ Scope of Variables Star pattern in C++ using for Loops 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 infinite loop in C++ Loops in C++ Auto keyword in C++ C++ STL (Standard Template Library) Divide by Zero Exception in C++ Dynamic Constructor in C++ Dynamic Memory Allocation in C++ Floating Point Operations and Associativity in C, C++ and Java Implementation of a Falling Matrix in C++ Message Passing in C++ Pointer to Object in C++ Ways to Copy a Vector in C++ Structure Sorting (By Multiple Rules) in C++ Similarities between C++ and Java 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++ Structured Binding in C++ Functors in C++ Lambda Expression 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++ Features of OOPS in C++ Hospital Management Project in C++ include Guards in C++ Iostream in C++ Method overriding in C++ Naming Convention in C++ Nullptr in C++ Object Slicing in C++ Principles of Object-Oriented Programming in C++ Processing strings using std string stream in C++ Random Number Generator in C++ Singleton Design Pattern in C++ Size_t Data Type in C++ Skyline Problem in C++ Web Development in C++ Data Hiding 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++ RTTI in C++ Pthreads or POSIX Threads in C++ Reserved Keywords 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++ Containership in C++ Counting Frequencies of Array Elements in C++ Decltype type Specifier in C++ Dynamic _Cast in C++ Features and Use of Pointers in C/C++ int Max and int Min in C/C++ is It Fine to Write Void Main Or Main in C/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 Pointers in C++ Abstract Factory Design Pattern in C++ Ascending order in C++ Call by Pointer in C++ Constexpr in C++ Deadlock in C++ Design Patterns in C++ Factory Method for Designing Pattern in C++ Name Mangling and extern in C++ Preventing Object Copy in C++ Quick Sort in C++ Single Handling in C++ Use of inheritance in C++ User-defined literals in C++ Vector methods in C++ Void * in C and C++ Zombie and Orphan Process in C++ List and Vector in C++ List iterators in C++ Merging Two Vectors in C++ Early Binding and Late Binding in C++ Factory Design Pattern in C++ Fisher-Yates shuffle algorithm in C++ for Auto in C++ Group anagrams in C++ Dynamic Casting in C++ 2D Vector initialization in C++ C++ GUI Visual Studio C++ IPC C++ Permutation Overloading Stream insertion in C++ Array sum in C++ STL C++ Define Macro C++ Design C++ Factory Pattern Convert String to Uppercase in 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++ Stack size in C++ Unordered_map in C++ Binary String to int C++ Boost C++ Exception handling in constructor and destructor in C++ Explain class template in C++ Kadane Algorithm in C++ Map of Pairs in STL Pair in C++ Access Specifiers in C++ Add Two Numbers in C++ Using Class C++ Socket Programming Windows Cube root in C++ C++ Protected inheritance C++ Return Object Static Data Members in C++ Association in C++ Boost libraries in C++ Automatic Storage Class in C++ C++ Move Constructor Cast in C++ C++ 11 Lambda C++ Multithreading Bottom-up Approach in C++ C++ Static Class C++ Static Member C++ Static Variable C++ Template Class Implementation Kruskals Algorithm in C++ Kth Permutation Sequence in C++ Kth Smallest Element Using Priority Queue in C++ Min Heap in C++ Multilevel inheritance in C++ Playfair Cipher Algorithm in C++ Exception Handling in Java and C++ Sorting in C++ Time and Space Complexity for Loops in C++ Convert Vector To String in C++ Cascading in C++ Control Structure in C++ Passing Object as argument in C++ Vector Pair in C++ String Data Types in C++ Topological Sort in C++ C++ Move Semantics C++ Static Library Linking Call by Value and Call by Reference in C++ Data Structures algorithms and application in C++ Dereferencing a Pointer in C++ Linked List in C++ All Swing Components in C++ anonymous Object in C++ Cerr in C++ Control Flow Statement in C++ cstdlib in C++ Exception Objects in C++ Base Class and Derived Class in C++ Creating A Menu in C++ Escape Sequence in C++ Explicit in C++ int range in C++ Maximum Value in Vector in C++ NPTEL Programming in C++ Shared Pointer in C++ Static Member Function in C++ With Example The Diamond Pattern in C++ Const ptr C++ Const_Cast C++ Area Of Triangle in C++ Array input in C++ Cin String in C++ Coroutine in C++ Gui Design in C++ integer in C++ Advantages and Disadvantages of inheritance in C++ C++ IDE Linux C++ Mini Project With Source Code And Output C++ Variables Types Containers in C++ Dynamic Binding in C++ Explain Access Specifiers in C++ Iomanip in C++ Noexcept in C++ C++ Reference Initializer in C++ Constant Arguments in C++ Vector in C++ Stl Singleton Pattern in C++ Error Handling in C++ C++ Thread Id to Int C Str in C++ C++ Shared Ptr Scope Resolution Operator in C++ C++ Random Number Between 1 and 10 File Opening Mode in C++ New and Delete in C++ Big Integers in C++ Stack Unwinding in C++ C++ Syntax Link Map cbegin() and cend() function in C++ STL Hamming Code Implementation in C++ Files and Streams in C++ Private Destructor in C++ Semaphore in C++ Map Emplace_hint() function in C++ STL Complex Number Program in C++ Meta Classes in C++ C++ Delegates Custom Sort in C++ RAII in C++ Babylonian Square Root Algorithm in C++ File Input and output operation in C++ Sum of Digits of a Number in C++ C++ Type Traits Binary Search Tree Program in C++ Tree in C++ Built in Types in C++ Catch all Exceptions in C++ C++ Template Class Declaration and Definition C++ Generic Programming Introduction Fundamental Data Types in C++ API in C++ Menu Driven Program in C++ Exception Specification in C++ Bit Manipulation in C++ Dynamic Initialization Of Objects in C++ Returning Object from a Function in C++ Class and Structure in C++ Edmonds Karp Algorithm in C++ Flush in C++ Find Substring in C++ Input and Output Operators in C++ Final in C++ Lvalue and Rvalue in C++ C++ Singleton File Stream in C++ Has a Relationship in C++ Character Set in C++ Menu Driven Program in C++ Final Keyword in C++ Associative Containers in C++ Decltype in C++ Insert Function in C++ Metaclass in C++ Move Constructor in C++ Move Semantics in C++

Features and Use of Pointers in C/C++

What is a pointer?

A pointer is mainly used to store the address of another variable. The * operator creates a pointer variable, which points to a data type (like an int) of the same type. The pointer is given the address of the variable you are working with.

However, each variable has its address in addition to its value (or, put, where it is in the Memory). The address can be obtained by prefixing the variable name with an ampersand (&).

The Use of Pointers in C/C++

A variable's address will appear utterly random if you print it on the screen (moreover, it can be different from run to run). Computer memory consists of bytes. Each byte has a fixed number of bits, 8 for most types of computers. A number identifies each byte called its address. Variables in a C or C++ program correspond to a series of bytes with consecutive addresses.

The lowest of these consecutive addresses is the address of the variable. A pointer is a variable that holds an address. Pointers to void hold addresses of bytes, and pointers to a type of hold addresses of variables of that type. Address 0 is not considered to be a valid address. But it's common in C and C++ for pointers to be set to address 0, which means they are not pointing to anything.

Technically, a pointer is the same thing as a size_t(unsigned long long) variable. We use them to store memory addresses. But there is more to it than just that.

You see, to the programmer and the compiler, a pointer represents two things:

1. The memory address that it points to.

2. The "type" of the data it points to.

How does the "type of the data" help?

  • It helps with readability (If I see an (int*).
  • It helps with pointer arithmetic.

E.g., in a 32bit Environment, an int pointer would jump 4 bytes ahead when you do a pointer++. Because sizeof(int)=4, but a char pointer would only jump 1 byte because the size of(char) is 1.

There are two types of pointers:

1)Pointers to primitive types.

2)Pointers to user-defined types.

But the data that a pointer holds is always the same kind-" Memory address."

Syntax:

datatype *var_name;

Example:

int *ptr;

Where int is the datatype and ptr is the pointer.

Declaration

Int *ptr=&var;

A pointer is initialized using a variable address after being declared, just like standard variables. The outcomes are unexpected and fatal if pointers in C programming are not uninitialized and utilized in the program.

We put the ampersand (&) operator before the name of a variable whose address we need to obtain to obtain its address. The syntax for initializing pointers is as follows.

Program

#include <iostream>
#include<bits/stdc++.h>
using namespace std;


int main()
{
    int a=10;
    int *ptr=&a;
    cout<<*ptr<<endl;


    return 0;
}

Output:

10

Another way to declare the pointer:

#include <iostream>
#include<bits/stdc++.h>
using namespace std;


int main()
{
    int a=10;
    int *ptr;
    ptr=&a;
    cout<<*ptr<<endl;


    return 0;
}

Output:

10

If the value is changed in the pointer, then changes will also be reflected in the original variable.

#include <iostream>
#include<bits/stdc++.h>
using namespace std;


int main()
{
    int a=10;
    int *ptr;
    ptr=&a;
    *ptr=20;
    cout<<"Pointer: "<<*ptr<<endl;
    cout<<"Variable: "<<a<<endl;


    return 0;
}

Output:

Pointer: 20
Variable: 20

If a variable is changed, pointer will also be changed.

#include <iostream>
#include<bits/stdc++.h>
using namespace std;


int main()
{
    int a=10;
    int *ptr;
    ptr=&a;
    a=20;
    cout<<"Pointer: "<<*ptr<<endl;
    cout<<"Variable: "<<a<<endl;


    return 0;
}

Output:

Pointer: 20
Variable: 20

Features of pointers

  • Pointers conserve Memory.
  • Because data are modified with addresses or direct access to memory locations, pointers have faster execution times.
  • The pointers provide efficient access to Memory. The Memory is both assigned and released by the pointer. Thus, it may be claimed that the Memory of pointers is allocated dynamically.
  • Data structures employ pointers. They can represent both two-dimensional and multi-dimensional arrays.
  • Pointers allow access to any array without considering the subscript range.
  • For handling files, pointers are utilized.
  • To allocate Memory dynamically, pointers are utilized.

Pointer Types in C

The many types of pointers in C are as follows:

  • Null Pointer: We can produce a null pointer by assigning a null value at the pointer declaration. When the pointer has no given address, this approach is helpful. The value 0 is always present in a null pointer.
  • Void Pointer: A void pointer is also known as a generic pointer in C programming. There is a variety of data types for it. The keyword void creates a pointer to a void. Any variable's address may be stored in it.
  • Wild pointer: If a pointer is not being initialized to anything, it is referred to as a wild pointer. These C pointer types are inefficient because they might point to an unidentified memory location, which could interfere with our program and cause it to crash. When using wild pointers, one should always exercise caution.

Advantages of pointers

  • For gaining access to memory regions, pointers are helpful.
  • An array structure's elements can be accessed effectively via pointers.
  • Both deallocation and dynamic memory allocation require pointers.
  • Complex data structures, like linked lists, graphs, trees, etc., are created using pointers.

Drawback of pointers

Pointers are very powerful, but with great power comes great danger. You could accidentally overwrite a system file just because your pointer contained a garbage value. Bugs are common in software; if even one of those bugs contains naked pointers, your computer is at risk.

So, to avoid that danger, HLLs hide pointers behind the implemented data structures and discourage programmers from using them. They encapsulate and obscure pointers so much that you could be programming for thirty years, and you wouldn't realize that you were using pointers.

For all practical purposes, the APIs will suffice. But if you are trying to super-optimize your program, you should investigate the low-level languages and pointers. If you use the pointer such that efficiency would suffer due to extra overhead before reaching the target, you are using pointers incorrectly.

Uses of pointers

  1. Pointers can save space

    Space is very precious & saving space leads to gaining time and, thus, better performance. Suppose you're working with very large data types or you have yourself have created an enormous object. Now, if you want to pass this object to a function, then the compiler will generate a copy of this object in the Memory, then this copy will be passed to the function & then the processing on the value will begin. In this way, you need to use the Memory efficiently because you must create a copy of such a large object without any good reasons. But suppose you pass the address of this variable to the target function. In that case, the processing will be done directly on the original object & hence no time or Memory will be wasted on the duplication of the original object. Thus speed & space efficiency is gained.
  2. They can increase speed during iterative traversal

    For example, if you wish to traverse the array, then you'll write a for loop to iterate the index value, but in actuality, you are incrementing the memory address. So, if you're performing conscious back-end coding, then instead of first incrementing the index & then updating the memory address, you can directly access the following memory location & hence performance improvement.
  3. Changes made are observed everywhere

    Suppose you have a program with independent threads. Now instead of creating a copy of the same data for each one, you provide them with the address of the original value & thus, if any change is made to the value, then every thread will get the latest updates.
  4. Reading variables not in the same scope

    Using pointers, you can access variables which were not declared in the same scope.
  5. Another reason for using pointers is that they enable dynamic memory allocation. For the allocation of dynamic memory, pointers are required. When working with an unknown amount of data, dynamic memory allocation comes in handy since it enables you to build variables, arrays, and more complicated data structures in memory while the program is executing.
  6. Pointers can also be used in storing elements in the array and accessing those elements from the array. Because the array variable also has an address that a pointer can point to, and the array can be navigated using a pointer.

Example:

#include <stdio.h>
int main() {
    int a[5];


    printf("Enter elements: ");
    for (int i = 0; i < 5; ++i)
        scanf("%d", a + i);


    printf("You entered: \n");
    for (int i = 0; i < 5; ++i)
        printf("%d\n", *(a + i));
    return 0;
}

Output:

Enter elements: 1 2 3 4 5
You entered: 
1
2
3
4
5

Summary

Pointers are used for memory purposes; when using normal data types, you're reserving a memory location for them, whether you use them once or several times. So, with an extensive program would significantly affect the Memory, making the program slower or demanding more Memory from the machine.

Pointers are very useful, and there is a must when going to next-level programming, unlike other languages like java which doesn't contain pointers. Therefore, pointers are a complex and yet most helpful thing in C and C++ programming languages.