How to join a string and DWORD?

Question

There is this function :

void func(const char *)

and I wanna use it like :

DWORD dWrd = 19;
func("I am " + dWrd + " years old!")

thanks..

Okay, I got this another function very related to the question above, hope I don't violate any rules.

So what if I have this function that accepts an argument that it would print using cout and write to a file isinf fstream, what data type should I use?

void myFunc(char c) ?

void myFunc(const char c) ?

void myFunc(const char *c)?

Find a C++ beginner's tutorial, it will cover this ;) – spectras Oct 26 '18 at 11:41 — spectras, Oct 26 '18 at 11:41
_string_ like in `std::string` or like in C string? – Scheff's Cat Oct 26 '18 at 11:41 — Scheff's Cat, Oct 26 '18 at 11:41

Cory Kramer · Accepted Answer · 2018-10-26T11:48:31.983

3

You could convert everything to a std::string then use c_str to get a const char*

func(("I am " + std::to_string(dWrd) + " years old!").c_str())

To be a bit more verbose (and avoid the implicit conversions)

func((std::string("I am ") + std::to_string(dWrd) + std::string(" years old!")).c_str())

Be careful regarding what you do with the const char* within func as once the function returns the temporary std::string will be destroyed and the pointer is no longer valid.

edited Oct 26 '18 at 11:48

answered Oct 26 '18 at 11:41

Cory Kramer

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^^what Scheff said. We don't have enough information in the question to answer this with confidence. – spectras Oct 26 '18 at 11:44
1

This answers their question of how to concatenate strings and numeric values. If they have issues with memory management, they can elaborate their question or ask a new question. – Cory Kramer Oct 26 '18 at 11:45
well, not std::string, as mentioned above, it's like a C string, wasll this solution work? – jordan cedrick Oct 26 '18 at 11:55
If your function has the signature `void func(const char *)` yes this will work. – Cory Kramer Oct 26 '18 at 11:56
thanks, guess this answers everything. I'll try and accept this answer . – jordan cedrick Oct 26 '18 at 12:00

BattleTested_закалённый в бою · Answer 2 · 2018-10-26T14:45:49.243

0

Use of std::ostringstream :

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

int main()
{
   DWORD dWrd = 19;
   std::ostringstream out;  
   out << "I am " << dWrd << " years old!";
   func(out.str().c_str());
}

edited Oct 26 '18 at 14:45

answered Oct 26 '18 at 12:02

BattleTested_закалённый в бою

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this seems a good answer but I think the code above will work better for my situation, since it only uses one line – jordan cedrick Oct 26 '18 at 12:04
@jordancedrick this is better, because its simplest than `std::to_string(dWrd)` – BattleTested_закалённый в бою Oct 26 '18 at 12:08
@jordancedrick If you want to concatenate more numbers with strings, you have to use of more statements to convert numbers to strings, BUT with `std::ostringstream` you just use of `<<` between numbers and strings.... – BattleTested_закалённый в бою Oct 26 '18 at 12:10

How to join a string and DWORD?

2 Answers2