Making a string from multiple doubles and char C++

Question

I'm trying to make a string out of a couple doubles and a character. I know my code here is wrong but I think it gives an idea of what I want to do.

operand2 = A.pop();     //double
operand1 = A.pop();     //double
math = "-";             //char
result = "%f %s %f",operand1, math, operand2;     //string
A.push(result);

I have tried researching how to do this. I am unfamiliar with sprintf and sprintcat, but is that the best method to go about doing this? Thank you so much for any input!

Since you're using C++, why not use [std::string](http://www.cplusplus.com/reference/string/string/)? — David Schwartz, Jan 28 '14 at 23:08
http://stackoverflow.com/questions/4983092/c-equivalent-of-sprintf#4983095 — SGM1, Jan 28 '14 at 23:09
If you want to use the C library, you make a reasonable buffer `char buff[50];` and then you `sprintf(buff, "%f %c %f", operand1, math, operand2);` I DO NOT RECOMMEND THIS — SGM1, Jan 28 '14 at 23:13

score 1 · Answer 1 · answered Jan 28 '14 at 23:15

1

double operand2 = A.pop();
double operand1 = A.pop();
char math = '-';
std::ostringstream oss;
oss << operand1 << ' ' << math << ' ' << operand2;
std::string result = oss.str();
...

answered Jan 28 '14 at 23:15

Remy Lebeau

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score 0 · Answer 2 · answered Jan 28 '14 at 23:14

Try this on for size.

You can be specific and use std::ostringstream, etc. But due to laziness this example makes use of std::stringstream instead.

#include <iostream>
#include <sstream>

// ...

double operand2 = A.pop();
double operand1 = A.pop();

std::stringstream stream;
stream << operand1 << " - " << operand2;
A.push(stream.str());

Making a string from multiple doubles and char C++

2 Answers2