How do you append an int to a string in C++? [dupl

Question

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• How to concatenate a std::string and an int? 29 answers

int i = 4;
string text = "Player ";
cout << (text + i);

I'd like it to print Player 4.

The above is obviously wrong but it shows what I'm trying to do here. Is there an easy way to do this or do I have to start adding new includes?

Answer 1

cout << text << i;

The << operator for ostream returns a reference to the ostream, so you can just keep chaining the << operations. That is, the above is basically the same as:

cout << text;
cout << i;

Answer 2

For the record, you could also use Qt's QString class:

#include <QtCore/QString>

int i = 4;
QString qs = QString("Player %1").arg(i);
std::cout << qs.toLocal8bit().constData();  // prints "Player 4"

Answer 3

The easiest way I could figure this out is the following..
It will work as a single string and string array. I am considering a string array, as it is complicated (little bit same will be followed with string). I create a array of names and append some integer and char with it to show how easy it is to append some int and chars to string, hope it helps. length is just to measure the size of array. If you are familiar with programming then size_t is a unsigned int

#include<iostream>
    #include<string>
    using namespace std;
    int main() {

        string names[] = { "amz","Waq","Mon","Sam","Has","Shak","GBy" }; //simple array
        int length = sizeof(names) / sizeof(names[0]); //give you size of array
        int id;
        string append[7];    //as length is 7 just for sake of storing and printing output 
        for (size_t i = 0; i < length; i++) {
            id = rand() % 20000 + 2;
            append[i] = names[i] + to_string(id);
        }
        for (size_t i = 0; i < length; i++) {
            cout << append[i] << endl;
        }


}

Answer 4

If using Windows/MFC, and need the string for more than immediate output try:

int i = 4;
CString strOutput;
strOutput.Format("Player %d", i);

Answer 5

You can use the following

int i = 4;
string text = "Player ";
text+=(i+'0');
cout << (text);

Answer 6

Here a small working conversion/appending example, with some code I needed before.

#include <string>
#include <sstream>
#include <iostream>

using namespace std;

int main(){
string str;
int i = 321;
std::stringstream ss;
ss << 123;
str = "/dev/video";
cout << str << endl;
cout << str << 456 << endl;
cout << str << i << endl;
str += ss.str();
cout << str << endl;
}

the output will be:

/dev/video
/dev/video456
/dev/video321
/dev/video123

Note that in the last two lines you save the modified string before it's actually printed out, and you could use it later if needed.