String/Char problems ....again...

When am i going to learn this....

I am trying to add one and one char to a char array. And then print it out using TextOut(...). But I have problems trying to add them. I tried using sprintf, but it adds a " " char in start and **** up everything if I do it like this.

Code:

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//cText is a double array [20][256]
//and teksten is just a single char.
sprintf(cText[iAntTekst], "%c%c", cText[iAntTekst], teksten);

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Anyone know how to fix this. There is one things I hate in C++ and that is strings....never handeled them very well...:(

First, why do you use C strings in C++?

Second, obviously it is not going to print a proper char if what you pass is a char[256]!
sprintf(cText[iAntTekst], "%c%c", cText[iAntTekst], teksten);

try specifiying the first argument as a string:

Code:

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sprintf(cText[iAntTekst], "%s%c", cText[iAntTekst], teksten);

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(or)

Code:

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int i  = strlen(cText[iAntTekst]);
cText[iAntTekst][i] = teksten;
cText[iAntTekst][i + 1] = '\0'

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anyway, the std::string class would be a lot easier.

Quote:

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Originally posted by CornedBee
First, why do you use C strings in C++?

Second, obviously it is not going to print a proper char if what you pass is a char[256]!
sprintf(cText[iAntTekst], "%c%c", cText[iAntTekst], teksten);

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First of all I told you I know nothing about strings in C/C++, it was my teacher that showed me the sprintf function, but I later found out that I had to add letters to the string. And then everything was ****ed....I am a graphics guy, not a string guy....guid me...:D

Quote:

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Originally posted by sunburnt
try specifiying the first argument as a string:

Code:

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sprintf(cText[iAntTekst], "%s%c", cText[iAntTekst], teksten);

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(or)

Code:

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int i  = strlen(cText[iAntTekst]);
cText[iAntTekst][i] = teksten;
cText[iAntTekst][i + 1] = '\0'

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anyway, the std::string class would be a lot easier.

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Well I don't have the code here, so I can't test the first one, I will do it at school tomorrow tho'. But I ended up doing it like in the second example there, but it looks like it is so much work to do so little. Just wanted to find a nice add a char to my string/char table. I have never worked with text at all, so consider me as a new guy here. Well the TextOut() function want a LPCTSTR, and I think that is *TCHAR. So I have no idea what a string actualy is in C++...for me everything looks like a char array...

a LPCTSTR is a long pointer to a const TCHAR -- ie const TCHAR*. a TCHAR is just a #define that is either char or wchar_t depending on whether or not you are compiling using unicode.

OK.....so did anyone wanted to tell me what a string was? And what that easy way was?

Thanks

A string in its simplest meaning (but not simplest usage) is just that: a string of characters, or sequence of characters. Somewhere in memory there's a continuous block filled with valid numbers from some character set, and that's a string. Usually, it's a NUL-terminated string, meaning that the last character has the value 0 to indicate the end of the string.
Ok, the way in C to achieve that was through
1) A string literal. "Hello" makes the compiler create that character sequence. Usually this is read-only memory.
2) A character array: char buf[100]; creates a space in memory large enough to hold 100 characters. That's 99 usable characters, because the terminating 0 needs a space.
3) malloc, which creates space on the heap.

In cases 1 and 3, a character pointer was used to refer to the memory.
const char *lit = "Hello";
char *bla = malloc(100);

The big problem with C strings is that you have to do the memory management yourself. A slightly smaller problem is that you have to use weird functions (strlen, strcpy, strcat, sprintf) to work with the strings.

In C++, we have classes, and suddenly we can do very pleasant stuff.

Code:

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#include <iostream>
#include <sstream>
#include <string>
using std::string;
using std::cout;
using std::endl;
using std::ostringstream;

#include <windows.h>

int main()
{
  string str = "Hello";  // Create a string.
  str += ", World!";  // Append a string
  str += '\n'; // Append a single character.
  // Do some weird formatting.
  int i = 300;
  float f = 82.48001f;
  ostringstream oss;
  oss << "The integer is " << i << " and the float is " << f << ".";
  str += oss.str();

  // And now pass the whole thing to MessageBox:
  MessageBox(0, "Caption?", str.c_str(), 0);
}

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You can use std::string's c_str() whereever a LPCTSTR is expected, such as TextOut - though strictly seen, you should use something a little different, but let's not go there.

Well thanks for that tutorial...that was very helpfull. Sorry I don't have the time to test all of that right now. But I will do it when I have time and get back to you.

Thanks.
ØØ