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++ 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

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++ Ascending order in C++ How the value is passed in C++ Call by Pointer in C++ Constexpr in C++ Deadlock in C++ Design Patterns in C++ Factory Method for Designing Pattern in C++ How to calculate size of string in C++ Name Mangling and extern in C++ Preventing Object Copy in C++ Program that produces different results in C and C++ Quick Sort in C++ Single Handling in C++ Type difference of Character literals in C VS 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++ Isprint() in C++ List and Vector in C++ List iterators in C++ Merging Two Vectors in C++ Sleep function in C++ Stoi function in C++ String erase() in C++ String Trim in C++ When should we write own Assignment operator in C++ C++ tcp client server example C++ tcp server example 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++ 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++ 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++? rint(), rintf(), rintl() in C++ Stack size in C++ String append() function in C++ String push_back() in C++ String replace() in C++ Transform function in C++ Unique in C++ Unordered_map in C++ Binary String to Int C++ Boost C++ ctime() function in C++ Difference Between Overloading and Overriding in C++ Exception handling in constructor and destructor in C++ Explain class template in C++ Fesetround() and Fegetround() in C++ and their application Gets() and Puts() in C++ Hypot(), hypotf() and hypotl() in C++ Kadane Algorithm in C++ Log function in C++ Map of Pairs in STL Map vs unordered_map in C++ Nearbyint() Function in C++ Pair in C++ Access Specifiers in C++ Add Two Numbers in C++ Using Class Benefits of Operator Overloading in C++ C++ Socket Programming Windows C++ Program for Addition of Two Numbers Using Functions C++ Programming Examples C++ Protected Inheritance C++ Return Object Static Data Members in C++ Program for COPY Constructor in C++ Association in C++ C_str in C++ Boost libraries in C++ C++ macro function Assignment Operator Overloading in C++ Automatic Storage Class in C++ Function Object in C++ C++ Move Constructor Cast in C++ C++ 11 Lambda C++ Multithreading Bottom-up Approach 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++ f 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++ Abstract Factory Design Pattern 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++ Semaphores in C++ Seekg in C++ stacktrace Header file in C++ 23 std::future in C++ std::unary_negate() in C++ Difference between std::endl and \n in C++ Iswspace Function 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++ UDP server- client implementattion in C++ What is long long in C++ CSV file management using C++ fma() function in 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 Exception Objects in C++ Difference between Null String and Empty String in C++ Character data type in c++ Constructors in Inheritance C++ Comma Operator Overloading in C++ Typename in C++ C++ Friend Class 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++ Factorial of Large Numbers in C++ endl Function in C++ vfprintf() method in C++ Check if a given number is Pronic in C++ Difference between Fundamental Data Type and Derived Data Types in C++ Different Ways to initialize an unordered_set in C++ Dinic’s Algorithm in C++ How to read whole ASCII File into C++ using std::string? std::unary_negate() in C++ String::npos function in C++ type_traits::is_null_pointer in C++ C++ code to count the local extrema of given array Demlo number (square of 11....1) in C++ Function Template and Class Template in C++ Getline in C++ GUI Design in C++ Hashing Implementation in C++ HIERARCHICAL INHERITANCE IN C++ Hospital Management System in C++ How to Add Header Files in Dev C++? How to cin string in C++ How to compile a C++ program in Visual Studio code Iscntrl in C++ Memento Pattern in C++ Smarandache-Wellin Sequence in C++ The feclearexcept in C++ HashMap in C++ Alexander Bogomolny's UnOrdered Permutation Algorithm in C++ Convex Polygon in C++ Count Univalue Subtrees in C++ Entringer Number in C++ Friends pairing Problem in C++ Klee's Algorithm (Length of the union of segments of a line) in C++ Spaceship Operator(&|t;==>) in C++ Uniform Initialization in C++ Woodall Number in C++ C++ Program to Solve Knapsack Problem Using Dynamic Programming How do you exit from the infinite loop in Turbo C++? How to create a game using C++ language How to do XOR in C++? How to Find Max Value in Array C++ How to get date in C++ Pointer to a Derived Class in C++ C++ program to show runtime exceptions Convert a Singly LinkedList to XOR LinkedList in C++ Creation of Variable in C++ CRTP (curiously recurring template pattern) in C++ Euler Circuits in Directed Graphs Using C++ Final NBA Match pairing in C++ Find pivot in rotated sorted array in C++ How to make a square in C++ How to reduce fractions in C++ std::lerp in C++ Stella Octangula Numbers in C++ Return Statement in C++ Finding the n-th Fortune Number in C++ How to use StringStream in C++ Minimize Count of Unequal Elements at corresponding Indices between give n arrays in C++ std::midpoint in C++ std::transform inclusive scan in C++ std::span in C++ Types of Errors in C++ C++ program to implement the bin packing algorithm Dereference Operator in C++ How to merge multiple std::sets into a single std::set in C++? Stack Clear C++ Structure and Class in C++ Template Definition in C++ Tree Data Structure in C++ Typename in C++ Program in C++ for Beginners Restoring a Shuffled Queue in C++ Print patterns in C++ Hybrid Inheritance in C++ How to use OpenGL in C++? How to Separate a String in C++ Havel-Hakimi algorithm in C++ Find the size of all connected Non-Empty Cells of a Matrix in C++ Burst Sort Algorithm in C++ Basic istream peak() method in C++ Addition of two matrices in C++ What is std reference wrapper in C++? What is std mbrtoc 32 in C++? What is std istreambuf iterator in C++? What is std declval in C++? std rethrow if nested in C++ std regex search in C++ std ctype byname in C++ std call once in C++ std basic ios copyfmt in C++ std atomic ref in C++ Properties of Friend Function in C++ Sophie Germain Prime number in C++ Centroid Decomposition in C++ How to Get the List of All Running Tasks in C++ Programming Questions on Function Overloading in C++ std codecvt in and std codecvt do in in C++ std is constant evaluated in C++ Std put money in C++ Number of ordered pairs such that Ai Aj = 0 in C++ dlsym() function in C++ Isxdigit() function in C++ Difference between Objective C and C++ Menu Driven Program in C++ Undulating Numbers in C++ How to Access Private Variables in C++? Particle Swarm Optimization in C++ Understanding std::ios_base::iword in C++ std::piecewise_construct _t in C++ Toeplitz Matrix in C++ Two-Way Linear Search Algorithm in C++ C++ Concurrency in action C++ integer size C++ Enum class Compare two lists in C++ Command to run C++ Program in terminal Cascading In C++ Static Member Function in C++ with Example C++ Multiple, Multilevel and Hierarchical inheritance Painting Fence Algorithm in C++ Rearrange Distant Barcodes in C++ What are the rules for using an Underscore in a C++ dentifier? std::quoted in C++ Std::memory_order in C++ Std::fisher_f_distribution in C++ Advantages Oops in C++ floor() and ceil() function in C++ Topological Sort in C++ How to get file size in C++ Class Meaning in C++ DIFFERENCE BETWEEN NEW AND DELETE OPERATOR IN C++ New and Delete In C++ Operators in C++ String data types in C++ begin() in C++ Static Library Linking in C++ Stack Unwinding in C++ Singleton Pattern in C++ Shared_ptr in C++ Random Number between 1 and 10 in C++ Initializer in C++ Error Handling in C++ Define Reference in C++ Create a Class in C++ C++ Move Semantics What is Thread Id to Int in C++? What is a Static Member Function in C++? Using Keyword in C++ C++ IDE Linux C++ Mini Project With Source Code and Output All swing components C++ Syntax Link Call By Value And Call By Reference In C++ Const ptr c++ Const_cast C++ Constant Arguments in C++ Example of parameterized constructor in C++ example of user-defined data type Anonymous object in C++ Bank program in C++ Base class and Derived class in C++ Cerr in C++ Cin string in C++ cin.get() in C++ Containers in C++ Control flow statement in C++ coroutine in C++ cstdlib in C++ Difference between encapsulation and Abstraction Difference between template and macro in C++ Emplace_back in C++ Cstdio in C++ Exception specification in C++ Files and streams in C++ Hamming code implementation in C++ Map cbegin() and cend() function in C++ STL Map Emplace_hint() function in C++ STL Naked function calls in C++ Private destructor in C++ Static object in C++ unordered_set in C++ Uses of namespace std in C++ Virtual function and virtual base class in C++ VS Code Setup for C++ Vtable and vptr in C++ fixed() function in C++ How to remove an element from an array in C++ How to take space-separated input in C++ iomanip in C++ Isdigit() function in C++ noexcept in C++ rdbuf() in c++ seekg() function in C++ Seekp() function in C++ Setw() in C++ The diamond pattern in C++ Advantages and Disadvantages of Inheritance in C++ C++ Variables Types Explain Access Specifiers in C++ Anagram Program in C++ AREA OF TRIANGLE IN C++ ARRAY INPUT IN C++ Big Integers in C++ Bitwise Operator in C++ Data Structures Algorithms and Application in C++ EOF Function in C++ Explicit in C++ File Opening Mode in C++ Friend Function in C++ Function Overriding in C++ How to Copy in Turbo C++? How To Use POW in C++ Increment Operator in C++ Inline Functions in C++ Int range in C++ Integer in C++ Linked List in C++ malloc() and calloc() in C++ Maximum Value in Vector in C++ NPTEL Programming in C++ Assignment Solutions SHARED POINTER IN C++ Vector in C++ Stl What is an Object in C++ What is Copy Constructor in C++ Dereferencing a Pointer in C++ fill() Function in C++ map find() function in C++ Associative Containers In C++ C++ generic programming introduction Character Set in C++ Class and Structure in C++ Decltype in c++ Difference Between Abstraction and Interface in C++ File Stream in C++ Final in C++ Final Keyword in C++ Find substring in C++ Flush in C++ Has-A Relationship in C++ How to allocate memory dynamically in C++ How to close turbo C++ in windows 10 How to Use Modulus in C++ How to use Set in C++ Input and Output Operators in C++ Insert Function in C++ MENU DRIVEN PROGRAM IN C++ MOVE SEMANTICS IN C++ OOPs Interview Questions in C++ PARAMETER PASSING IN C++ PUNCTUATORS IN C++ SPLIT FUNCTION IN C++ Stream Classes in C++ Vector declaration in c++ Vector in C++ Virtual Function in C++ Binary Search Tree Program in C++ Built-in Types in C++ API in C++ Returning Object from a Function in C++ C++ Singleton C++ Template Class Declaration and Definition Tree in C++ C++ Type Traits Catch All Exceptions in C++ Lvalue and Rvalue in C++ Move Constructor in C++ Move Semantics in C++ Mutex Lock in C++ Qt in C++ Tutorial STL Algorithms in C++ Access Class members in C++ Designated initializers in C++ Dynamic Initialization of Objects in C++ Inbuilt Functions in C++ Metaclass in C++ Nesting of a member function in C++ Unique_ptr() in C++ Vector erase() function in C++ Vector insert() Function in C++ 10 important concepts of Oops in C++ At in C++ Difference Between Abstraction and Encapsulation in C++ Difference between Function Overloading and Operator Overloading in C++ Exception Specifications in C++ Examples of Destructor in C++ Examples of Hybrid Inheritance in C++ How to declare an Array in C++ How to declare string in C++ Instance variable in C++ Manipulators in C++ Pointer Declaration in C++ preprocessor in C++ Push_Back() Function in C++ Space in C++ String stl in c++ Edmonds Karp algorithm in C++ How to Create Singleton Class in C++ Static Polymorphism in C++ Associative Containers In C++ C++ generic programming introduction Character Set in C++ Class and Structure in C++ Decltype in c++ Difference Between Abstraction and Interface in C++ File Stream in C++ Final in C++ Final Keyword in C++ Find substring in C++ Flush in C++ Has-A Relationship in C++ How to allocate memory dynamically in C++ How to close turbo C++ in windows 10 How to Use Modulus in C++ How to use Set in C++ Input and Output Operators in C++ Insert Function in C++ MENU DRIVEN PROGRAM IN C++ MOVE SEMANTICS IN C++ OOPs Interview Questions in C++ PARAMETER PASSING IN C++ PUNCTUATORS IN C++ SPLIT FUNCTION IN C++ Stream Classes in C++ Vector declaration in c++ Vector in C++ Virtual Function in C++ Associative Containers In C++ C++ generic programming introduction Character Set in C++ Class and Structure in C++ Decltype in c++ Difference Between Abstraction and Interface in C++ File Stream in C++ Final in C++ Final Keyword in C++ Find substring in C++ Flush in C++ Has-A Relationship in C++ How to allocate memory dynamically in C++ How to close turbo C++ in windows 10 How to Use Modulus in C++ How to use Set in C++ Input and Output Operators in C++ Insert Function in C++ MENU DRIVEN PROGRAM IN C++ MOVE SEMANTICS IN C++ OOPs Interview Questions in C++ PARAMETER PASSING IN C++ PUNCTUATORS IN C++ SPLIT FUNCTION IN C++ Stream Classes in C++ Vector declaration in c++ Virtual Function in C++ Babylonian Square Root Algorithm in C++ C++ Delegates Complex Number Program in C++ Custom Sort in C++ Differences Between C++ and JavaScript Meta Classes in C++ Prim’s Algorithm in C++ RAII in C++ How to access set elements in C++ How to Allocate and Deallocate Memory in C++ How to Convert String to Lowercase in c++ How to initialize a string in C++ How to Input a String in C++ Ignore Function in C++ Image Recognition Algorithm in C++ Insertion Sort Algorithm in C++ Knapsack Problem in C++ LOG BASE 2 IN C++ LOOPING STATEMENT IN C++ Managing Output with Manipulators in C++ Max Heap in C++ mbrlen- function in C-C++ Merge Overlapping Intervals in C++ Merge Sort Recursive in C++ Methods to Sort Strings in C++ Multiline Comment in C++ Multiple catch statements in C++ Naïve Bayes Algorithm in C++ Needleman Wunsch Algorithm in C++ Object delegation in C++ Pass 2 Assembler Program in C++ ratio_less_equal() function in C++ Rethrowing an exception in C++ Return type in C++ Reusability in C++ Round Robin Scheduling Program in C++ Sequence Container in C++ Sieve of Eratosthenes in C++ SOLID PRINCIPLES IN C++ STACK USING PUSH POP PROGRAMME IN C++ Stdlib Header File in C++ Strcmp function in C++ strcmpi in C++ Find minimum s-t cut in a flow network in C++ Hamilton Cycle Detection in C++ list cbеgin() and cеnd() function in C++ Maximum Bipartite Matching in C++ Neural Network in C++ Otsu Thresholding Opencv C++ Pancake Sorting in C++ Pimpl Idiom in C++ Print All Interleavings of Given Two Strings in C++ Print the Corner Elements and their Sum in a 2-D Matrix in C++ reinterpret_cast in C++ Rotate Bits of a Number in C++ Shallow Copy in C++ Stable Marriage Program in C++ Stack Smashing Detected in C++ Static Data Member in C++ String::npos in C++ Thread safe queue in C++ Total Keywords in C++ Tug of War in C++ What Kind of Exceptions are Available in C++ Which Operator is Used to Allocate Memory for an Object Boundary Traversal of Binary Number in C++ Difference between POP and OOP in C++ Fundamentals of Data Structures in C++ C++ Constructor Return Type C++ Libraries C++ STL Tutorial C++ Throw Character String in C++ Clone a Linked List with Next and Random Pointer in C++ Counting Sort in C++ Diffеrеncе Bеtwееn dеquе::cbеgin and dеquе::assign in C++ Difference between Null and Nullptr in C++ Facade Pattern in C++ Semaphore in C++ Accumulate function in C++ Algorithm Header File in C++ Applications of C++ basic_istream::putback() in C++ Benefits of OOPs Boost library in C++ Bubble Sort in C++ C++ Override C++ Struct Public Throw Exception in C++ Call by Rеfеrеncе in C++ Character in C++ Characteristics of friend function in C++ Cin Getline in C++ Collections in C++ Composition in c++ Continue Statement in C++ Developing a Digital Synthesizer in C++ Different C++ Versions Diffеrеncе Bеtwееn Friеnd Function and Virtual Function in C++ Find a triplet from three linked lists with a sum equal to a given number in C++ Fizz Buzz Problem in C++ Forward list in C++ Friend Function and Friend Class in C++ Advantages of Function Overloading in C++ Game Library for C++ HashSet in C++ Heapify Algorithm in C++ Hopcroft Karp algorithm in C++ String find function in C++ Tellg in C++ The lower_bound in C++ The sum of digits in C++ Thinking in C++ language THIS FUNCTION IN C++ Tower of Hanoi Algorithm in C++ Transpose of a Matrix in C++ language Types of Execution in C++ Use of explicit keyword in C++ User-defined header files in C++ Vector of String in C++ Virtual Table in C++ Visibility Mode in C++ What are Literals in C++ What are manipulators in C++ Abstract Data Type in C++ POP full form in C++ 8-puzzle Problem Using Branch and Bound in C++ BK tree in C++ Decorator pattern in C++ Fusion tree in C++ Jump Pointer algorithm in C++ std::remove_extent in C++ Tabu search in C++ Nested structure in C++

Const_cast C++
2024-07-19 06:47:07

Const_cast C++

The source pointer's const behaviour can be altered or modified using the const_cast. It indicates that we have two options for doing the const: either setting a const pointer to a non-const pointer or deleting or removing the const from a const pointer.

Constness or volatility of an object can be eliminated using the C++ type casting operator const_cast. It gives you the option to alter a variable's consistency or volatility, perhaps allowing adjustments that were previously forbidden.

Immutable variables in C++ are declared using the const keyword. However, there may be times when you need to make changes to a variable that was initially defined as const. Here, const_cast enters the picture. It offers a method to remove a variable's constness, enabling you to change its value.

Const_cast has the following syntax:

const_cast<type>(expression);

Here, type denotes the desired type to which the expression should be cast, and expression denotes the expression or variable from which the constness should be removed. The expression must be of a pointer or reference type, it is very crucial to remember this.

Const_cast is a function that enables you to change an object that was first declared as const. However, if the original variable was genuinely declared as const at its initialization, using const_cast to change a variable marked as const is undefined behaviour. The constness contract is immediately broken when an object is modified, which can result in unexpected behaviour and programme flaws.

It is important to use const_cast judiciously and only when absolutely necessary. Modifying const objects can introduce bugs and make your code harder to reason about. Ideally, you should avoid declaring variables as const if you anticipate the need to modify them later.

Const_cast can also be used to remove a variable's volatility. In C++, the volatile qualifier is used to indicate the potential for an unanticipated change in a variable value, typically brought into by external forces. If you wish to treat a volatile variable as a non-volatile one, Const_cast is used to remove the volatility from it.

Sample program for how to use const_cast is given below:

#include<iostream>

void modifyValue(int* ptr) {

    (*ptr)++;

}

int main(){

    const int value = 42;

    const int* constPtr = &value;

    // Error: Attempting to modify a const object

    // (*constPtr)++;

    int* nonConstPtr=const_cast<int*>(constPtr);

    modifyValue(nonConstPtr);

    std::cout<<"Modified value:" << value << std::endl;

    return 0;

}

Output:

Const_cast C++

In this example, we have a variable value declared as const. We also have a pointer constPtr pointing to value. Without const_cast, we wouldn't be able to modify value directly through constPtr.However, by dereferencing nonConstPtr inside the modifyValue function, we can edit value indirectly by using const_cast to cast constPtr to a non-const pointer.

It's crucial to stress that const_cast should only be used sparingly and carefully. Const correctness of your programme can be violated and unexpected behaviour can result from changing const objects. Avoiding declaring variables as const if you anticipate the need for modification in the future is generally seen as good practise.

Considerations:

There are a number of factors to take into account and best practises to follow when using const_cast in C++ to guarantee appropriate and secure usage:

  • Const_cast should only be used when absolutely required, and only after having a thorough knowledge of the implications.
  • Modifying a const object through const_cast can lead to undefined behavior if the original object was actually declared as const during initialization.
  • Document the rationale: If you find yourself using const_cast, make sure to document the rationale behind it. Explain why the constness needs to be cast away and provide clear justification for the modification. This helps other developers understand the intent and potential risks associated with the code.
  • Consider alternative designs: Instead of relying on const_cast, consider alternative designs that avoid the need for modifying const objects. This may involve reevaluating your program's architecture, data flow, or design patterns to accommodate the necessary modifications without violating constness.

Different ways of using cont_cast in c++:

In C++ const_cast can be used in different situations to modify the constness or volatility of objects. Below are the common use cases for const_cast:

•          Remove constness and modify a non-const object

•          Casting away constness to pass an object to a function

•          Removing volatility to treat a volatile object as non-volatile

•          Type punning to reinterpret the memory as float

1. Remove constness and modify a non-const object

Sample program which is used to demonstrate how to use const_cast to remove constness and modify a non-const object:

#include<iostream>

int main(){

    const int value = 42;

    // Attempting to modify a const object

    // value++;

    int& nonConstRef =const_cast<int&>(value);

    nonConstRef++;

    std::cout <<"Modified value:" << value << std::endl;

    return 0;

}

Output:

Const_cast C++

In this program, we have a variable value declared as const. Initially, if we try to modify value directly (as shown in the commented line), it will result in a compilation error because value is const.

To modify value, we use const_cast to cast away the constness of value and create a reference nonConstRef that refers to value. We can then modify value indirectly by modifying nonConstRef.

As you can see the output, value has been successfully modified even though it was initially declared as const. However, keep in mind that changing const objects using const_cast is typically not advised unless you have a compelling reason to do so, as doing so will result in unexpected behaviour and compromise the program's const correctness.

Don't forget that it's typically regarded as best practise to refrain from defining variables as const if you think they might need to be changed in the future rather than depending on const_cast to do so.

2.Casting away constness to pass an object to a function:

Example program in C++ that demonstrates how to use const_cast to pass a const object to a function that expects a non-const argument:

#include<iostream>

void modifyValue(int* ptr) {

    (*ptr)++;

}

int main(){

    const int value = 42;

    // Attempting to pass a const object directly

    // modifyValue(&value);

    int* nonConstPtr = const_cast<int*>(&value);

    modifyValue(nonConstPtr);

    std::cout << "Modified value: " << value << std::endl;

    return 0;

}

Output:

Const_cast C++

The function modifyValue in this programme increases the value to which a pointer to an int points when it receives an argument. Value, a const int variable, has a value of 42 at the beginning.

Because we are attempting to give a const object to a function that requires a non-const argument, the compiler will throw an error if we attempt to pass value directly to modifyValue as demonstrated in the commented line.

In order to fix this, we cast away the value's constness and retrieve a non-const pointer to it using const_cast.

We store the result in nonConstPtr, which is then passed as an argument to modifyValue. By casting away the constness, we can modify the value indirectly through nonConstPtr.

After calling modifyValue, we print the value of value to verify that it has been modified successfully. In this case, the output will be:

Const_cast can be used to change a const object's value, however it is generally not advised because it can cause unexpected behaviour and compromise the const correctness of your programme. Casting or directly altering const objects might bring problems and make your code more difficult to understand.

3.Removing volatility to treat a volatile object as non-volatile:

sample program which will demonstrates the usage of const_cast to remove volatility and treat a volatile object as non-volatile:

#include<iostream>

int main(){

    volatile int volatileValue = 42;

    // Volatile value before modification

    std::cout << "Volatile value before modification: " << volatileValue << std::endl;

    // Casting away volatility using const_cast

    int* nonVolatilePtr = const_cast<int*>(&volatileValue);

    // Modifying the value through the non-volatile pointer

    *nonVolatilePtr = 100;

    // Volatile value after modification

    std::cout << "Volatile value after modification: " << volatileValue << std::endl;

    return 0;

}

Output:

Const_cast C++

In this program, we have a volatile integer variable volatileValue initialized with a value of 42. The volatile qualifier indicates that the value of volatileValue may change unexpectedly, typically due to external factors.

We use const_cast to convert the address of volatileValue into a non-volatile pointer of type int* so that we can consider volatileValue as a non-volatile object. The nonVolatilePtr variable receives the generated non-volatile pointer.

We then modify the value of volatileValue indirectly by dereferencing nonVolatilePtr and assigning a new value of 100 to it. This modification is possible because nonVolatilePtr points to the same memory location as volatileValue, but without the volatility qualifier.

Finally, we print the original volatile value and the modified value to observe the change. Keep in mind that the behavior of volatile objects can be implementation-specific, and modifying volatile objects may have unintended consequences. Therefore, it is essential to use const_cast and remove volatility only when necessary and fully understand the implications in your specific use case.

Note: the usage of const_cast to remove volatility should be approached with caution, as it can lead to unexpected behavior and violate the intended semantics of volatile objects.

4.Type punning to reinterpret the memory as float

float floatValue = *const_cast <float*> ( reinterpret_cast < const float* > ( valuePtr ) );

It is important to keep in note that if the original object was truly declared as const during its startup, using const_cast to change it may result in undefined behaviour. The constness contract is immediately broken when an object is modified, and this might lead to unexpected programme behaviour.

Therefore, it's imperative to apply caution and make sure that const_cast is required and appropriate in your particular circumstance.

Here is an sample program which will demonstrates the use of const_cast for type punning to reinterpret memory as a float in C++:

#include<iostream>

int main(){

    int intValue = 123456789;  // An integer value

    const int* intPtr = &intValue;

    // Type punning using const_cast

    float* floatPtr = const_cast<float*>(reinterpret_cast<const float*>(intPtr))

    // Accessing the memory as a float

    float floatValue = *floatPtr;

    // Printing the original integer value and the interpreted float value

    std::cout <<"Original Integer Value:" << intValue << std::endl;

    std::cout <<"Interpreted Float Value:" << floatValue << std::endl;

    return 0;

}

Output:

Const_cast C++

In this program, we have an integer variable intValue with the value 123456789. We then create a pointer intPtr that points to the memory location of intValue.

To reinterpret the memory as a float, we use const_cast in conjunction with reinterpret_cast. First, we use reinterpret_cast to reinterpret intPtr as a const float*. Then, we use const_cast to remove the const qualifier, obtaining a float*. This allows us to treat the memory originally occupied by an int as a float.

We then dereference floatPtr to access the memory as a float, storing the interpreted value in floatValue.

Please note that type punning through const_cast and reinterpret_cast can be a powerful technique, but it is also risky and can lead to undefined behavior. It is crucial to ensure that the original memory content and the reinterpretation are compatible and do not violate strict aliasing rules or alignment requirements.

Advantages:

The const_cast operator in C++ provides a way to remove the constness or volatility of an object, allowing for certain advantages in specific scenarios.

 Here are some potential advantages of using const_cast:

  • Working with legacy code: const_cast can be useful when dealing with legacy codebases that contain const-qualified variables. In some cases, you may need to modify these variables due to certain requirements or changes in your application. const_cast allows you to work around the constness and modify those variables when necessary.
  • Interoperability with C libraries: C libraries often use non-const interfaces for functions that do not modify their arguments, even if those arguments are logically constant.Const_cast can be used to temporarily remove the arguments' constness when interacting with such libraries from C++, allowing you to call library functions without encountering compilation issues.

Disadvantage

Const_cast has various drawbacks and dangers that you should be aware of when using it in C++, despite the fact that it can be useful in some circumstances:

  • Const_cast's main drawback is that it lets you change an object that was previously declared as const, which is a violation of const correctness.
  • Modifying const objects can lead to unexpected behavior and introduce bugs in your code. It violates the const correctness principle, which is designed to ensure that const objects remain unmodifiable. Using const_cast to modify const objects can make your code harder to understand and reason about.
  • while const_cast can provide a way to modify const objects or remove volatility, it comes with inherent risks and disadvantages.
  • Modifying const objects can lead to undefined behavior, violate const correctness, introduce bugs, reduce code maintainability, and decrease code readability.
  • It is crucial to use const_cast judiciously and only when absolutely necessary, understanding the potential consequences and seeking alternative design approaches whenever possible.