Introduction to C++ Int to String

When you write programs for your software there are multiple instances where you might need to convert a given number from integer to string and maybe from string to integer data type in C++ programming. In this article, we will discuss integer to string conversion through different methods using C++ libraries. Make sure you always provide a valid string because it will generate an error in case if the string is not valid. However, we can check the string validity through different functions available in the coding language. There is basically two most common method for converting a string.

Given below are the two methods with the syntax for converting a string from integer data type to string data type:

By using the to_string() method in your code.

string string_name = to_string (x);

In the above syntax, string_name can be anything a user wants but the parameter x passing into string function is the string defined by the user for conversion.

By using stringstream class.

stringstream string_name;

In the above syntax, string_name can be anything a user wants but an insertion operation will be needed to insert the parameter into string defined by the user for conversion.

How to Convert Integer to String in C++?

Below are the different examples to convert C++ integer to string. Basically there are 2 ways to convert Integer to string in C++.

Example #1 – Using String Stream Class

stringstream class is a C++ stream class defined in the header file of code. To perform input-output operations. This stream class is used to perform string-based operations. Here is the C++ code to demonstrate the conversion of integer to string by using stringstream class:

Code:

#include <iostream>
#include <sstream>
using namespace std ;
int main () {
int x ;
cout << " Please Enter an integer value for converting to string " ;
cin >> x ;
stringstream ss ;
ss << x ;
string s ;
ss >> s;
cout << " \n " << " The value of an integer is : " << x << " \n " ;
cout << " The string representation of an integer value is : " << s ;
}

Output:

Code Explanation: In the above code, you can see we have a main class with an integer x and a stringstream class. We have taken an input integer value from the user to convert it to a string using a stringstream class of C++ programming language. If you see the code properly we have included library names as stream to use the functionality of stream classes.

Example #2 – Using to_string() Method

Code:

#include <iostream>
#include <string>
using namespace std ;
int main ()
{
int x = 152 ;
float y = 25.69 ;
string str1 = to_string ( x ) ;
string str2 = to_string ( y ) ;
cout << " The string value of integer x is : " << str1 << " \n " ;
cout << " The string value of float y is : " << str2 ;
}

Output:

Code Explanation: In the above code, you can see we have a main class with an integer x and a float y inside the main class. Then we have defined two strings that we want to convert. One is str1 and another is str2. Therefore, with the help of the to_string() function, we can use these string of int and float and then convert it into string respectively by using to_string() function. We have taken an input integer value and a float value from the user to convert it to a string using the to_string() function of the string class of C++ programming language. If you see the code properly we have included library names as the string to use the functionality of string classes.

Example #3 – Using to_string() Method

Code:

// How to convert a number to string.
#include <iostream>
#include <string>
using namespace std ;
int main ()
{
// Declaring an integer
int int_val = 510 ;
// Declaring a float
float flo_val = 250.20 ;
// Conversion of an int into string using a to_string () method
string str1 = to_string ( int_val ) ;
// Conversion of float into string using to_string () method
string str2 = to_string ( flo_val ) ;
// Displaying the converted strings into given formats
cout << " The integer value in the string is : " ;
cout << str1 << endl ;
cout << " The float value in the string is : " ;
cout << str2 << endl ;
return 0 ;
}

Output:

Code Explanation: In the above code, you can see we have a main class with an integer value int_val and a float value flo_val inside the main class. Then we have defined two strings that we want to convert and we are passing the integer and float value as a parameter in the to_string() method. One is str1 and another is str2. Therefore, with the help of the to_string() function, we can use these string of int_val and flo_val and then convert it into string respectively by using to_string() function. We have taken an input integer value and a float value from the user to convert it to a string using the to_string() function of the string class of C++ programming language. If you see the code properly we have included library names as the string to use the functionality of string classes.

Conclusion

Conversion C++ Int to String becomes easy when we use the above-mentioned method and class. Otherwise, if we are going to implement traditional ways for conversion then it will require more memory space and time which will affect the coding efficiency.