Can we insert a variable inside a string? Please help me

Question

Example:
Int a,b,sum;
Cin>>a>>b;
String str("is the result");
Sum=a+b;
How we can insert variable(sum) at the beginning of the string?

Answer 1

#include <string>
#include <iostream>
#include <sstream>
using namespace std;

int main()
{
int sum, num1, num2;

cin >> num1 >> num2;
sum = num1 + num2;

// using stringstream
ostringstream ss;
ss << sum << " is the result\n";
string res1 = ss.str();
cout << res1;

// alternatively using `to_string`
string res2 = to_string(sum) + " is the result\n";
cout << res2;
return 0;
}

Answer 2

Hi
https://code.sololearn.com/cLCDk37spWE7/?ref=app

Answer 3

I have tried
str.insert(0,sum);
But it doesn't worked