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++

C++ int into String

Data type conversion is a standard editing process. You may need to convert variable from one type of data to another in a variety of situations. There are two ways to modify data types: ambiguous type conversion (producer-made) and transparent-type conversion (user-generated) (manual). Explicit type conversion is available in many editing languages with built-in methods.

If you convert data from a complete format to a character unit, you may use it to run multiple character unit functions. Compared to the function of a character unit, the performance of arithmetic can be difficult. Consider the following scenario for printing a current date.

C++ int into String

An integer can be converted to a string in three ways:

  • The stringstream class is used.
  • The to_string() function is used.
  • By utilising boost.lexical cast.

Using stringstream class to convert an integer to a string.

A stream class defined in the header file is stringstream. It's a stream class that lets you execute input-output actions on strings.

The operations used to insert or extract data are as follows:

  • It pulls data from the stream using the operator >>.
  • The operator<< enters data into the stream.

Let's look at an example to better comprehend the notion of operators.

  • The insertion operator puts 100 into the stream in the sentence below.
    stream1 << 100;
  • The >> extraction operator extracts data from the stream and saves it in the  x variable in the sentence below.
    stream1 >> x.

Example :

#include <iostream> 
#include <bits/stdc++.h>
#include <stdlib> 
#include<sstream>  
using namespace std;  
int main() {  
  int x;  
  cout<<"enter an integer value";  
  cin>>x;  
  stringstream sst;  
  sst<<x;  
  string a;  
  sst>>a;  
  cout<<"\n"<<"An integer value is : "<<x<<"\n";  
  cout<<"String representation of an integer value is : "<<a;   
}  

OUTPUT:

Enter an integer value 14
An integer value is: 14
String representation of an integer value is : 14
........................................................
Process executed in 4553.34 seconds
Press any key continue.

Explanation:

We generated the k variable in the previous example and wish to convert its value to a string value. The stringstream class has been used to transform the x integer value into a string value. We can also do it the other way around, converting a string to an integer value using simply the stringstream class.

Let's look at an example to better grasp the notion of string to number conversion.

#include <iostream>
#include <bits/stdc++.h>
#include <stdlib>  
#include<sstream>  
using namespace std;  
int main()  
{  
  string number ="99";  
  stringstream sst;  
  ss<<number;  
  int x;  
  sst>>x;  
  cout<<"The value of the string is : "<<number<<"\n";  
  cout<<"Integer value of the string is : "<<x;  
}  

OUTPUT:

The value of the string is : 99
Integer value of the string is : 99
.......................................................
Process executed in 0.33 seconds
Pres any key to continue.

Explanation

In the above program in C++, string number is 99 and string stream we are using to generate x variable.

Using to_string() method to convert an integer to a string.

The to_string () method takes a single integer and turns it to a string using the to_string () method.

Example:

#include <iostream>  
#include <stdlib>
#include <bits/sdtc++.h>
#include<string>  
using namespace std;  
int main()  
{  
 int x=14;  
 float y=16.2;  
string str= to_string(x);  
string str1= to_string(y);  
cout<<"string value of integer x is :"<<str<<"\n";  
cout<<"string value of y is : "<< str1;  
return 0;
}  

OUTPUT:

string value of integer x is : 14
string value of y is : 16.200000
.................................................
Process executed in 2834.44 seconds
Press any key to continue.

Explanation

In the above example in C++, we are using to_string method to convert integer number to string number which is a predefined number in C++.

Using boost.lexical method to convert an integer to a string.

The boost.lexical cast package includes a cast operator, boost.lexical cast, that transforms a string value to an integer or other data type value and back.

Let's look at an example of how to convert an integer to a string using boot.lexical method:

#include <iostream>  
#include <bits/stdc++.h>
#include <stdlib>
#include <string>
#include <boost/lexical_cast.hpp>  
using namespace std;  
int main()  
{  
int x=12;   
string str = boost::lexical_cast<string>(x);  
cout<<"string value of integer x is :"<<str<<"\n";  
}  

OUTPUT:

string of integer x is : 12
...............................................
Process executed in 323.32 seconds
Press any key to continue.

Explanation:

Using the lexical cast () method, we transformed the value of the x variable into a string value in the above example.

Another Example:

#include <iostream> 
#include <bits/stdc++.h>
#include <stdlib>
#include <string> 
#include <boost/lexical_cast.hpp>  
using namespace std;  
int main()  
{  
string str="5678";  
 int b = boost::lexical_cast<int>(str);  
cout<<"Integer value of string str is : "<<b<<"\n";  
}  

OUTPUT:

Integer value of string str is : 5678
..............................................................
Process Executed in 427.36 seconds
Press any key to continue.

Explanation

We used the lexical cast () method to turn the string value into an integer value in the previous example.

One more example to understand better:

#include <boost/lexical_cast.hpp> // for lexical_cast()
#include <iostream>
#include <string> // for string
using namespace std; 
int main()
{
// Declaring float
float f_value = 13.4;


// Declaring int
int x_value = 19;


// lexical_cast() converts a float into string
string strf = boost::lexical_cast<string>(f_value);


// lexical_cast() converts a int into string
string strx = boost::lexical_cast<string>(x_value);


// Displaying string converted numbers
cout << "The float value in string is : ";
cout << strf << endl;
cout << "The int value in string is : ";
cout << strx << endl; 
return 0;
}

OUTPUT:

The float value in string is : 13.4
The int value in string is : 19

Explanation

In the above example in C++, Her we used a lexical_cast.hpp library which is a method of using lexical() to turn the string value into an integer.



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