Re: C Style Strings

From:

"kwikius" <andy@servocomm.freeserve.co.uk>

Newsgroups:

comp.lang.c++,comp.lang.c

Date:

1 Jun 2006 01:15:08 -0700

Message-ID:

<1149149707.969131.264550@u72g2000cwu.googlegroups.com>

scroopy wrote:

Hi,

I've always used std::string but I'm having to use a 3rd party library
that returns const char*s. Given:

char* pString1 = "Blah ";
const char* pString2 = "Blah Blah";

How do I append the contents of pString2 to pString? (giving "Blah
Blah Blah")

#include <malloc.h>
#include <cstring>

char* concat(const char * str1, const char* str2)
{
    char * result = (char*) malloc(strlen( str1) + strlen (str2) + 1);
    if( result != NULL){
        strcpy(result,str1);
        strcat(result, str2);
    }
    return result;
}

#include <iostream>
#include <string>

char* pString1 = "Blah ";
const char* pString2 = "Blah Blah";

int main()
{
    // C-style
    char* str = concat(pString1,pString2);
    if(str != NULL){
        std::cout << str <<'\n';
        free(str);
    }

    // C++ style
    std::string str1=std::string(pString1) + pString2;
    std::cout << str1 <<'\n';
}

I'm not sure if that is the optimal C method. Its interesting to note
how much better the C++ version is though!

regards
Andy Little