Code won't compile! O.o

Just need someone to tell me where I'm going wrong... :)

Would someone kindly look over my small program? It's 150 lines long BUT has much commenting, so will be easy to understand. Actual program coding is ~100 lines. Very short and simple. I have tried many things but no luck, so I thought an experianced coder could pick up the syntax errors or whatever.

I have finished writing what I want it to do...

User inputs Roman numeral, it converts it to Arabic. *done*
User inputs Arabic numeral, it converts it to Roman. *done*
User inputs text file, converts it to Roman, outputs to new text file. *done*
User inputs text file, no calculation to convert to Arabic yet. :mad:

But I'm not asking for help with that, I would like someone to have a quick scan through to see why its not compiling, check syntax etc... so it runs and works.

I don't wish to post the code on here as it is coursework, so please reply with contact info or add me to MSN or email me: <snipped>

Rich :)

How about instead paying attention to what your compiler is saying? You know, the actual reason why it's not compiling. There really is a reason to read those lines after all.


Quzah.

The least you could have done is posted the errors you were getting, and the lines of code that they referred to.

I highly doubt that (and hope not) anybody is going to contact you to personally go through your code. The point of a forum is so everyone can benefit from the replies and posts, it's not your personal support service.

I have read the errors im getting and have tried many things to sort it.

Code:

---

Compiling...
miniproject.cpp
miniproject.cpp(1) : warning C4067: unexpected tokens following preprocessor directive - expected a newline
miniproject.cpp(24) : error C2143: syntax error : missing ';' before '{'
miniproject.cpp(24) : error C3861: 'arabicToRoman': identifier not found, even with argument-dependent lookup
miniproject.cpp(25) : error C2065: 'output' : undeclared identifier
miniproject.cpp(26) : error C2065: 'input' : undeclared identifier
miniproject.cpp(26) : fatal error C1903: unable to recover from previous error(s); stopping compilation

---

Code:

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        arabicToRoman() {
                output = "";
                while (input >= 1000) {
                        output = output + "M";
                        input - 1000;
                }

---

first line here is line 24 in the program. arabicToRoman() is a procedure.. i dont know what it means by identifier not found. and "output" "input" are indentified. *sigh*

Quote:

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Originally Posted by cwr

The least you could have done is posted the errors you were getting, and the lines of code that they referred to.

I highly doubt that (and hope not) anybody is going to contact you to personally go through your code. The point of a forum is so everyone can benefit from the replies and posts, it's not your personal support service.

---

Why do you hope that someone wont go through my code. Not asking them to fix it all, just tell me where i'm going wrong so I can fix it. How am i supposed to learn if i dont know the right way.

Well, this is a C forum, but you appear to be posting (edit: or trying to compile C as ) C++. I'm not a C++ person, but I recall that C++ won't let you have bare functions without an explicit return value. In C, your function declaration above is valid but dodgy. You should use int arabicToRoman(void) { or void arabitToRoman(void) { depending on whether it returns something. (int could be another type)

Another issue is that you should have a prototype of the function above.

As for output and input, where are they declared? Unless they're global (outside any function), it won't be in scope for your arabicToRoman function.

I don't hope someone won't go through your code, my point was that you shouldn't expect people to personally contact you outside the forum to get help.

Edit:

Another thing, if this is C, and not C++, then the code you posted makes little sense. Assuming output is a char pointer or char array, such things won't work. You can't concatenate strings like that with a + operator. You may be able to do such magic in C++, though.

It's meant to be C. but using ms visual c++

the procedure deals with numbers and characters, so what do i use? float arabicToRoman(void) ?

it sends the value to the "output" variable.

It's very simple:

If your function is to take no arguments, declare it's argument list as void. Otherwise, stick whatever arguments you're going to pass to it as types, in the order you wish them to be passed. For example, if I have a function that is to take an integer and a float, I might do something like this:

Code:

---

void myfunction( int a, float b )
{
    ...stuff here...
}

---

Likewise, if the function is not going to return anything, we make it have a void return type. Otherwise, we pick the one type we wish to return. Possibly like so:

Code:

---

int myfunction( int a, float b )
{
    ...stuff goes here...
    return (something here that's an int);
}

---

Now then, if you're going to have something called output and input, you need those variables to actually be declared some place. You aren't declaring any variables inside your function, which means it can't see anything called output and input, unless you have them declared as global variables some place in scope.


Quzah.

Post all your code. It also appears you have a severe lack of understanding regarding the mechanics of C strings. You need to pick up a book, or read some tutorials.

Quote:

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Originally Posted by Coldcore

It's meant to be C. but using ms visual c++

---

In addition to what's been said above, I suggest you convince your compiler to compile it as C code instead of C++, if possible.

There are things that are legal in C but not in C++, and obviously vice versa, and there are things that are legal in both, but have different results.

Some background.

This may also be of interest. [A search for "roman numerals" by "Prelude": results as posts -- I just happened to know that.]

Ahh looks interesting, i'll give that a read now, thanks!

Wow your code is really really bad.

1 - You use all global variables.
2 - The function main should be returning an int. There's a FAQ on it.
3 - You are trying to have nested functions, which is not allowed.
4 - You are confusing the assignment operator with the equality operator. = assigns a value. == tests for equality.
5 - You keep trying to assign strings to floating point numbers.


Quzah.

>_< I know it's bad. I kind of built it up to make it look like what i want it to do then i make it work... ill try sort the things you've mentioned. Thanks.

Another suggestion..

you have around 150 lines of code there.. that is... well quzah summed it up..

maybe you should try to build your program a little by little... get one *small* part working, then add somthing new. this way when you introduce a bug in the middle of writing it, you are not running all over the place trying to figure out what the problem is. you can narrow it down to what you changed last and what it affected..

get the point..

and of course pay attention to all the previous posts..

I've fixed all but 1 error in my code which the compiler comes up with:

Quote:

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error C2664: 'fopen' : cannot convert parameter 1 from 'char' to 'const char *'

---

It says this error for line 2 and 3 of the snippet below:

Code:

---

char line[8];
ifp=fopen(inputFileName, "r");
ofp=fopen(outputFileName, "w");
/* Calculate each line until end of file */
while(fgets(line, 8, ifp) != NULL) {
        sscanf (line, "%c", &inputRoman);
        /* Call calculation procedure */
        romanToArabic();
        /* Print result into output text file */
        fprintf(ofp, "The Arabic numeral for %c is %i", inputRoman, outputArabic);
}
fclose(ofp);
fclose(ifp);

---

Outside of void main() is:

Code:

---

FILE *ifp, *ofp;
char inputFileName, outputFileName, inputRoman;
int outputArabic;

---

Quote:

---

Originally Posted by xhi

Another suggestion..

you have around 150 lines of code there.. that is... well quzah summed it up..

maybe you should try to build your program a little by little... get one *small* part working, then add somthing new. this way when you introduce a bug in the middle of writing it, you are not running all over the place trying to figure out what the problem is. you can narrow it down to what you changed last and what it affected..

get the point..

and of course pay attention to all the previous posts..

---

mate i know my code is crap but cant expect me to write this in the best way possible straight away. ive only ever done little programs to do small calculations before, this is the biggest program ive done and its nothin compared to what you guys can do i know. also, of that 150 lines of code is 40 lines of commenting. so 110 :P

Quote:

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Originally Posted by Coldcore

mate i know my code is crap but cant expect me to write this in the best way possible straight away. ive only ever done little programs to do small calculations before, this is the biggest program ive done and its nothin compared to what you guys can do i know. also, of that 150 lines of code is 40 lines of commenting. so 110 :P

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i am in no position to call other people code crap.. i can barely remember what i learned yesterday to apply it to what i learn today.. so i am merely trying to suggest what i do to help myself.. compile often and fix little bits as i go..

as for the current problem..

i would think that it is with these lines ..

char inputFileName, outputFileName, inputRoman;
ifp=fopen(inputFileName, "r");
ofp=fopen(outputFileName, "w");

fopen is looking for a string (const char*).. and you are giving it a char
try to do somthing like this..

fopen("infilename", "r")

or

char filename[] = "inFileName";
fopen(filename, "r");

You should also check to make sure the files were opened, especially the one opened in read mode.

And another thing:

Code:

---

output = output + "M";

---

I assume this is trying to add "M" on to the end of the string output. Use strcat() for string concatenation.

And re-read Quzah's post again. :)

There's an old saying that goes "No pain, no gain."

So many times I see folks in here posting messages like:

"Please look over my code. I'm not asking you to code my project, but I need to know why it doesn't work."

Your compiler -- if properly set up -- will tell you what's wrong with your program. The reason you're not understanding what it is telling you is because you haven't learned to translate all of those error messages into words that YOU understand. Your compiler tends to assume that you ARE an experienced C programmer. (Wouldn't it be great, though, if a compiler had a --newb switch, to put those error messages in newb-speak!)

The first time you pick over each and every compiler message, and figure out what it is telling you, it's a painful and time consuming process. But believe me, doing that will make you a better programmer.

Most folks who are taking a C course in college or in high school are just concerned with getting the program to run, so that they can turn it in and get the grade. But it is my opinion that the learning REALLY comes when you're picking your way through all the errors that your first effort turns up. That PAIN is where you find your GAIN.

If you run into a compiler message you don't understand, copy and paste it into the search box on Google. That one little act can save you hours of scratching your head. Yes, sometimes you have to sift through the chaff on Google before you find the wheat, but it IS helpful.

Do that for a while, and you start to get a feel for what will and won't work.

Now, all of that doesn't even begin to cover the process of debugging once you've gotten it to compile. But that's another topic for another day.

Don't hesitate to ask for help on the forums for something you don't understand, but also, don't shy away from picking apart those error messages.

Just my 2 cents worth......

xhi,

fopen("infilename", "r")

would having the variable "infilename" in quotes like this make it think thats the actual filename? the error dissapears using the quotes tho. the user inputs the text file name into the variable "inputFileName" and that is currently set to a char.. so is this why it needs to be in quotes to work? maybe it should be a float? ill read up on this later.

fgw_three,
thanks man.

I did this earlier actually, went through each error message on google and managed to fix all apart from an error I get which doesnt specify a line number because its a general error. I tried to look up the definition of this error but its too general so I really dont know what is wrong.

Quote:

---

test.obj : error LNK2005: _main already defined in miniproject.obj
Debug/miniproject.exe : fatal error LNK1169: one or more multiply defined symbols found

---

im sorry for being another noob asking that same old senario, i guess i was just trying to find the easy way out. but thanks to you guys im not finding that route, which i am thankful for because ive actually learnt a little going through these errors. and its a greater satisfaction when you fix them.

but this one i really am stuck on. ill carry on with trying to get it to work later today, and hopefully ill figure it out.

thanks again.

>> would having the variable "infilename" in quotes like this make it think thats the actual filename?

thats what i was getting at.. just as an example of what could be done.. if you did it this way infilename is what the file would be named just as if you did this..

fopen("somefile.txt", "r");

the file would be somefile.txt ..

Quote:

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I tried to look up the definition of this error but its too general so I really dont know what is wrong.

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You have more than one main() function, get rid of all but one.

ahh it was because i had another source file with main() in it, so i deleted that and now it compiles. now for the debugging