pointer increment error

can someone tell me what's wrong with this line of code pls?

Code:

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while(*buffer != "\0"){cout << static_cast<unsigned int>(*buffer); *buffer++;}

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I keep getting the error:

Quote:

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28 C:\Dev-Cpp\MyProjs\fencrypt.cpp ISO C++ forbids comparison between pointer and integer

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buffer is declared such:

Code:

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char buffer[90];

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thanks

The complaint is caused by the while-condition (*buffer != "\0"). *buffer is a char (an integral type). "\0" is a string, which the compiler sees as an array of char and (when doing comparisons) arrays are sometimes threated like they're pointers.

Even though it is not resulting in a complaint from the compiler, the body of the loop is highly suspect as well: even more so if you apply the obvious fix (make the two things being compared of the same type) so the compiler does not complain about about the while-condition.

Make "\0" a character literal: '\0'.

Then, get a separate pointer for traversing, because you can't increment an array.

Once you've done that, you might as well use a for loop, which is more suitable for this kind of task.

Code:

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for(const char *p = buffer; *p != '\0'; ++p) {
  std::cout << static_cast<unsigned int>(*p);
}

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There's several more ways to accomplish this. But this is the simplest.

I got around it my own way thanks :)
I now have a new problem. I output the converted string into a file, close the file then re-open the file with ios::in.
Even though the string is stored as an interger cast I can't cast back to the ascii form:

Code:

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while (!b_file.eof()) {
char i;
      i = static_cast<char>(b_file.get() );
      cout << i;
     
}

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still only outputs numbers, not the original string.

It's kinda silly to store all those chars as integers in the file (assuming you did, as you did cast the mess).
AFAIK, istream.get returns a reference to itself, so your code is invalid.
Further, using istream to read anything other than strings, might bite you later too. From my own experiments, of course.

You wrote the text serialization of the integer into the file, then you read individual bytes back and cast their numeric form to char - and you expect something even remotely similar to come out?

Oh, and about "while (!b_file.eof())", read the FAQ.

Quote:

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Oh, and about "while (!b_file.eof())", read the FAQ

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can't find anything in the FAQ related to it. Also could you explain what text serialisation is pls??

Quote:

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Originally Posted by WDT

can't find anything in the FAQ related to it.

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http://faq.cprogramming.com/cgi-bin/...&id=1043284351