C++ Tutorial Index

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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

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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 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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 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C++ Type Casting

The type casting of variables in the C++ programming language will be covered in this section. The term "type casting" describes how software converts one data type to another. There are two ways to typecast code: automatically by the compiler, and manually by the user or programmer. Type Conversion is another name for type casting.

Consider the situation when we wish to change the data from an integer type to a float type. Therefore, we must manually cast int data to the float type; in C++, this process is known as type casting.

int num = 5 ;  
float x ;  
x = float ( num ) ;  
x = 5 . 0  

Another example:

float num = 5 . 25 ;  
int x ;  
x = int ( num ) ;  

Implicit conversion, also known as Implicit Type Casting, and explicit type conversion, also known as Explicit Type Casting, are the two main forms of type casting.

Implicit Type Conversion vs. Implicit Type Casting

  • The automated type casting is what it is called.
  • Without any assistance from a user or programmer, it automatically converted between different data types.
  • It implies that a data type is automatically converted to another by the compiler.
  • Without sacrificing any information, every data type is immediately updated to the biggest kind.
  • It can only be used in a program if the two variables work well together.
char - sort int - > int - > unsigned int - > long int - > float - > double - > long double , etc. 

NOTE: Remember to do implicit type casting from lower to higher data types. Otherwise, it has an impact on the basic data type and may cause it to lose accuracy or data, in which case the compiler may flash a warning.

Example1: A program that makes advantage of C++'s implicit type casting

Let's construct an example to show how to cast one variable to another in C++ using implicit type casting.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;  
int main ( )  
{  
    short x = 200 ;  
    int y ;  
    y = x ;  
    cout << " Implicit Type Casting " << endl ;  
    cout << " The value of x : " << x << endl ;  
    cout << " The value of y : " << y << endl ;  
      
    int num = 20 ;  
    char ch = ' a ' ;  
    int res = 20 + ' a ' ;  
    cout << " Type casting char to int data type ( ' a ' to 20 ) : " << res << endl ;  
      
    float val = num + ' A ' ;  
    cout << " Type casting from int data to float type : " << val << endl ;   
    return 0 ;                                                                                     
}  

OUTPUT:

Implicit Type Casting
The value of x : 200
The value of y : 200
Type casting char to int data type ( ' a ' to 20 ) : 117
Type casting from int data to float type : 85
........................................................
Process executed in 2.11 seconds
Press any key to continue

Explanation

The short data type variable x is 200 and the integer variable y were both defined in the aforementioned application. After that, we assign the value of x to the value of y, at which point the compiler instantly translates x's short data value to y, returning y to be 200.

The character type variable ch is set to "a," which is equal to an integer value of 97, and the int type variable num is set to 20 in the following statements. The implicit conversion is then completed by adding these two variables, returning the expression's result of 117.

In the third statement, we do the same thing by adding the character variable ch to the integer variable num, which is 20, and assigning the result to the float variable val. As a consequence, the compiler automatically converts the expression's result to the float type.

Explicit Type Conversion vs. Explicit Type Casting

  • It is often referred to as a program's manual type casting.
  • Programmers or users must manually cast data to switch from one data type to another in a program.
  • It implies that a user may simply cast one data to another in accordance with a program's demand.
  • The compatibility of the variables need not be verified.
 (type) expression; //syntax of explicit casting
  • type: It symbolizes the user-defined information that transforms the supplied phrase.
  • expression: It symbolizes a constant value, variable, or expression whose data type has been changed.
int num ;      
num = ( int ) 4 . 534 ; // cast into int data type  
cout << num ;  

When the aforementioned commands are run, the cast () operator will convert the floating-point value into an integer data type. Additionally, the integer num that receives the float value is given a decimal truncation, showing just 4 as the integer value.

Example2: A program to show how to utilize C++'s explicit type casting

Let's make a straightforward program that uses the explicit type casting feature of the C++ programming language to convert a variable of one type into a different type.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;  
int main ( )  
{  
    // declaration of the variables  
    int a , b ;  
    float res ;  
    a = 21 ;  
    b = 5 ;  
    cout << " Implicit Type Casting : " << endl ;  
    cout << " Result : " << a / b << endl ; // it loses some information  
      
    cout << " \n Explicit Type Casting : " << endl ;  
    // use cast ( ) operator to convert int data to float  
    res = ( float ) 21 / 5 ;  
    cout << " The value of float variable ( res ) : " << res << endl ;  
      
    return 0 ;                             
}  

OUTPUT:

Implicit Type Casting :
Result : 4
Explicit Type Casting :
The value of float variable ( res ) : 4 . 2
........................................................
Process executed in 2 . 11 seconds
Press any key to continue

Explanation

Two integer variables, a and b, with the values 21 and 2, are used in the aforementioned program. Next, divide a by b (21/2), which yields a value of type 4 int.

Using the cast operator in the explicit type cast method, we define a float type variable res in the second expression that saves the outcomes of a and b without erasing any data.

Example3: Use the cast operator in a program to convert double data to int and float types.

Let's look at an example where double data is converted into float and int types in C++ programming to determine the area of a rectangle.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;  
int main ( )  
{  
    // declaration of the variables  
    double l , b ;  
    int area ;  
      
    / / convert double data type to int type  
    cout << " The length of the rectangle is : " << endl ;  
    cin >> l ;  
    cout << " The breadth of the rectangle is : " << endl ;  
    cin >> b ;  
    area = ( int ) l * b ; / / cast into int type  
    cout << " The area of the rectangle is : " << area << endl ;  
      
    float res ;  
    // convert double data type to float type  
    cout << " \n \n The length of the rectangle is : " << l << endl ;  
    cout << " The breadth of the rectangle is : " << b << endl ;  
    res = ( float ) l * b ; // cast into float type  
    cout << " The area of the rectangle is : " << res ;  
    return 0 ;                                                                                     
}  

OUTPUT :

The length of the rectangle is : 
57 . 3456
The breadth of the rectangle is :
12 . 9874
The area of the rectangle is : 740
The length of the rectangle is : 57 . 3456
The breadth of the rectangle is : 12 . 9874
The area of the rectangle is : 744 . 77
........................................................
Process executed in 2 . 31 seconds
Press any key to continue

Explanation

In the above example of a program in C++, we have demonstrated how double data is converted into float and int type.

There are several forms of type casting

In type cast, a cast operator compels the conversion of one data type into another in accordance with the requirements of the program. The cast operator comes in four different varieties in C++:

  • Static cast
  • Dynamic cast
  • Const cast
  • Reinterpret cast
static_cast < new_data_type > ( expression ) ;  //syntax of static casting

Example4: A program to show how to utilize a static cast

Let's make a straightforward example to demonstrate how to utilize the static cast of type casting in C++ programming.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;  
int main ( )  
{  
    // declare a variable  
    double l ;  
    l = 2 . 5 * 3 . 5 * 4 . 5 ;  
    int tot ;  
      
    cout << " Before using the static cast : " << endl ;  
    cout << " The value of l = " << l << endl ;  
      
    // use the static_cast to convert the data type  
    tot = static_cast < int > ( l ) ;  
    cout << " After using the static cast : " << endl ;  
    cout << " The value of tot = " << tot << endl ;  
    return 0 ;                                                                                     
}  

OUTPUT:

Before using the static cast:
The value of l = 39 . 375
After using the static cast :
The value of tot = 39
........................................................
Process executed in 2 . 11 seconds
Press any key to continue

Explanation

In the above example of a program in C++, we have demonstrated the method of utilizing static cast of type casting.

Dynamic Casting

Only class pointers and references can be converted from one type variable to another using the runtime cast operator dynamic cast. It entails that the casting of the variables is verified at runtime, and a NULL value is returned if the casting is unsuccessful.

Example5: A program to show how to utilize C++'s dynamic cast

Let's write a straightforward C++ application that uses the dynamic cast function.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;      
class parent  
    {  
        public : virtual void print ( )  
        {  
        }  
    } ;  
    class derived : public parent  
    {  
    } ;  
    int main ( )  
    {  
           // create an object ptr  
    parent * ptr = new derived ;  
    // use the dynamic cast to convert class data  
    derived * d = dynamic_cast < derived * > ( ptr ) ;  
    // check whether the dynamic cast is performed or not  
    if ( d ! = NULL )  
    {  
        cout << " Dynamic casting is done successfully " ;  
    }  
    else  
    {  
        cout << " Dynamic casting is not done successfully " ;  
    }  
    }  

OUTPUT:

Dynamic casting is done successfully.
........................................................
Process executed in 2 . 11 seconds
Press any key to continue

Explanation

In the above example of the program in C++, we have demonstrated the use of dynamic casting function which converted from one type variable to another using the runtime cast operator dynamic cast.

Example6: C++ program that makes advantage of the Reinterpret Cast

Let's create a program to show how to convert a pointer in C++ using the reinterpret function.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;      
int main ( )  
{  
    // declaration of the pointer variables  
    int * pt = new int ( 65 ) ;  
    // use reinterpre_cast operator to type cast the pointer variables  
    char * ch = reinterpret_cast < char * > ( pt ) ;  
    cout << " The value of pt : " << pt << endl ;  
    cout << " The value of ch : " << ch << endl ;  
    // get value of the defined variable using pointer  
    cout << " The value of * ptr : " << * pt << endl ;  
    cout << " The value of * ch : " << * ch << endl ;  
    return 0 ;  
}  

OUTPUT:

The value of pt : 0x5cfed0
The value of ch : A
The value of * ptr : 65
The value of * ch : A
........................................................
Process executed in 2 . 11 seconds
Press any key to continue

Explanation

In the above example of a program, we have demonstrated the conversion of pointer in C++ using the reinterpret function. This indicates that it does not verify if the pointer or the data it points to are identical.

Example7: A C++ program that use the Const Cast

Let's create a program that uses C++'s const cast function to cast a source pointer to a non-cast pointer.

#include < iostream > 
#include < bits/stdc++.h >
#include < stdlib >
#include < stdio > 
using namespace std ;      
// define a function  
int disp ( int * pt )  
{  
    return ( * pt * 10 ) ;  
}  
int main ( )  
{  
    // declare a const variable  
    const int num = 50 ;  
    const int * pt = # // get the address of num  
    // use const_cast to chnage the constness of the source pointer  
    int * ptr = const_cast < int * > ( pt ) ;  
    cout << " The value of ptr cast : " << disp ( ptr ) ;  
    return 0 ;  
} 

OUTPUT:

The value of ptr cast : 500
........................................................
Process executed in 2 . 11 seconds
Press any key to continue

Explanation

In the above example of a program in C++'s const cast function to cast a source pointer to a non-cast pointer. It implies that we have two options for doing the const: either changing a const pointer to a non-const pointer or deleting or removing the const from a const pointer.