Many time during implementing c++ logic or displaying string we require to convert int to string in c++. We have given different solution for c++ int to string conversion. Here we have provided solutions using std::to_string(), using std::ostringstream and using custom function to convert int to string in c++.
1) Int to string c++ ( Using std::to_string)
#include<iostream>#include <string>using namespace std;int main(){ int nInput = 123; string sOutput; //Using C++ 11 int to string conversion sOutput = to_string(nInput); cout << "1) Using std::to_string():" << sOutput << endl; return 0;} |
Here std:to_string function will convert into to string in c++. Generally this function is used in c++ 11. Here we will get input as string value “123”.
2) convert int to string c++ (Using std::ostringstream)
#include<iostream>#include <sstream>using namespace std;std::string NumberToString(int Number){ std::ostringstream ss; ss << Number; return ss.str();}int main(){ int nInput = 123; string sOutput; // c++ convert int to string using std::ostringstream sOutput = NumberToString(nInput); cout << "2) Using ostringstream:"<< sOutput << endl; return 0;} |
Here we are using std::ostringstream for c++ int to string conversion. For using it we will require to add header : include <sstream> .
3) C++ Int to string using custom function
#include<iostream>#include <algorithm>using namespace std;/** * C++ version 0.4 std::string style "itoa": * Contributions from Stuart Lowe, Ray-Yuan Sheu, * Rodrigo de Salvo Braz, Luc Gallant, John Maloney * and Brian Hunt */std::string CustomIntToStr(int IntValue, int nBase) { std::string sBuf; // check that the base if valid if (nBase < 2 || nBase > 16) return sBuf; enum { kMaxDigits = 35 }; sBuf.reserve(kMaxDigits); // Pre-allocate enough space. int quotient = IntValue; // Translating number to string with base: do { sBuf += "0123456789abcdef"[std::abs(quotient % nBase)]; quotient /= nBase; } while (quotient); // Append the negative sign if (IntValue < 0) sBuf += '-'; std::reverse(sBuf.begin(), sBuf.end()); return sBuf;}int main(){ int nInput = 123; string sOutput; // c++ int to string using cutom function sOutput = CustomIntToStr(nInput, 10); cout << "3) Using custom function: " << sOutput <<endl; return 0;} |
We have used custom function which is similar to itoa(), It will be used for c++ int to string conversion.
If we are using boost library then also we can implement using including #include “boost/lexical_cast.hpp”, and then use lexical_cast<string>(Integer).
CONCLUSION:
In c++ program whenever we want to convert int to string in c++, we will require to use any of given methods. If our c++ compiler support c++11 or advance version then it will be more easy task because c++11 onward it is improving and you will find many functions in boost library as well. I hope given article will be useful for you to convert int to string c++ easily in c++ 11 or older versions as well.
This is very easy, do the same thing during compile time. Convert int to string during compilation.