how to add a character variable to character array in c++

Question

I want to write the C++ code that can help me to give the drive letter which contains the given folder. I am writing the given code and getting the error while adding the character variable to a string variable at line 11. Can anyone help me out in rectifying the below code.

#include "stdafx.h"
#include <string>
#include <windows.h>
#include <iostream>
#include "Shlwapi.h"
int main()
{
    char var;
    for (var = 'A'; var <= 'Z'; ++var)
    {
        char buffer_1[] = var +":\\PerfLogs";      ------->>>> line where i am getting the error
        char *lpStr1;
        lpStr1 = buffer_1;
        int retval;
        retval = PathFileExists(lpStr1);
        if (retval == 1)
        {
            std :: cout << "Search for the file path of : " << lpStr1;
            system("PAUSE");
        }
    }
}

retval = PathFileExists((var + std::string(":\\PerfLogs")).c_str());. Alternatively, char buffer[] = "*:\\PerLogs"; buffer[0] = var; retval = PathFileExists(buffer); — HolyBlackCat
– HolyBlackCat, Commented Jun 18, 2018 at 11:49
Also note that your loop is not portable. Not all systems have character encodings where all letters are contiguous. — Some programmer dude
– Some programmer dude, Commented Jun 18, 2018 at 11:50
@Bathsheba: Let me rephrase it in a different way,then. Drive letters are already not portable. std::file_system has an abstract notion of root names, but their exact syntax is wholly unspecified by C++. The only thing you know is that they're represented as strings, and there's no way you can portably enumerate these strings. — MSalters
– MSalters, Commented Jun 18, 2018 at 12:08

Johan B · Accepted Answer · 2018-06-18 11:49:58Z

3

You should use the string library:

std::string str1="Str 1";
std::string str2=" Str 2";
str1.append(str2);      //str1 = "Str 1 Str 2"

answered Jun 18, 2018 at 11:49

Johan B

3941 silver badge10 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Puneet Garg Over a year ago

Thanks for the suggestion, its working fine over there but then I am not able to convert the same to char* type and i need to do that for accessing PathFileExists(lpStr1) function, any idea about that

HolyBlackCat Over a year ago

@PuneetGarg PathFileExists(your_string.c_str())

Bathsheba · Accepted Answer · 2018-06-18 12:43:31Z

2

The specific compiler error you get is due to your attempting to add a const char* type (as a result of a string literal decayed to a pointer type) to a char. Let's not worry too much about that; rather, let's put the C++ standard library to good use:

A portable solution would be as follows:

#include <iostream>
#include <string>
// ToDo - include the header for PathFileExists
using namespace std::string_literals; // Bring in the std::string user defined literal.

int main() {
    for (auto c : "ABCDEFGHIJKLMNOPQRSTUVWXYZ"s){ // Note the user defined literal.
        std::string path = c + ":\\PerfLogs"s; // And again. This calls an overloaded `+`.
        int retval = PathFileExists(path.c_str()); // Pass the char buffer.
        if (retval == 1){
            std::cout << "Search for the file path of : " << path;
            system("PAUSE");
        }
    }
}

edited Jun 18, 2018 at 12:43

answered Jun 18, 2018 at 11:55

Bathsheba

235k35 gold badges376 silver badges504 bronze badges

5 Comments

O'Neil Over a year ago

You're missing using namespace std::string_literals; and PathFileExists is declared in Shlwapi.h

Bathsheba Over a year ago

@O'Neil: On your first point, doesn't the string header bring that in? On the second point, no matter as there's nothing in the question to really point out which file system library they are using.

O'Neil Over a year ago

1) No it doesn't. 2) Except the #include of that file.

Puneet Garg Over a year ago

@Bathsheba thanks, It worked, and yes there is the need to use the namespace to define user define literals... thanks a lot everyone for your help.

Bathsheba Over a year ago

@O'Neil: Checked the first point, and yes, as you knew all along, you're correct.

Jonathan Mee · Accepted Answer · 2018-06-18 13:58:17Z

0

You can use std::string for this as others have suggested. But since it's just 1 character it wouldn't be too hard to do this:

const char buffer_1[] = { var, ':', '\\', 'P', 'e', 'r', 'f', 'L', 'o', 'g', 's', '\0' };

answered Jun 18, 2018 at 13:58

Jonathan Mee

39.1k26 gold badges148 silver badges319 bronze badges

Collectives™ on Stack Overflow

how to add a character variable to character array in c++

3 Answers 3

2 Comments

5 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

5 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related