char array write to file

Question

I have a struct called Product in which I have a variable called prodname:

char prodname[30];

The instance of the struct is called product

I wrote a method to check if the name entered by the user, is unique or not. In this method, I pass the value entered by the user to the method called checkprodname(char n[30])

In the main method

if(checkprodname(prodName) == 0)
    {
        gotoxy(21,13);
        printf("The Product Name that you have entered already exists.");
        getch();
        addproduct();
        return 0;
    }

Then after this I have this line of code:

product.prodname = prodName;

In order to assign the value in the temp variable prodName into the actual struct. Of course I will them move on to save all this into the file. But till now I am getting an error since this is the error I'm getting:

incompatible types when assigning to type char[30] from type char**

I already used the same logic for the prodid which worked; however when using the string, I have no idea how to arrive to the actual assigning of the value into the actual struct since I'm getting that error.

Any help would be appreciated.

Wes Miller · Accepted Answer · 2013-01-09 16:05:09Z

1

If you are in C++, consider replacing the char arrays with a std::string. Not that it makes all that much difference, but std::strings are usually easier to use. (IMHO)

answered Jan 9, 2013 at 16:05

Wes Miller

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1 Comment

Wes Miller Over a year ago

An afterthought. If you store the product structures in a std::map<std::string, Product> where the std::string is prodname (string-ified), you can easily check for the existence of a mapped member.

Jonathan Leffler · Accepted Answer · 2013-01-09 15:56:52Z

0

You can't assign arrays in C using that notation. For character strings, use strcpy(); for other arrays, use memmove() or memcpy(). In all cases, make sure there's enough space in the target to store what is in the source.

Normally, I'd expect to write:

strcpy(product.prodname, prodName);

Given the compilation warning you're getting, it appears you need to use:

strcpy(product.prodname, *prodName);

Given the discussion in the comments below, it appears that the first alternative was correct after all, but I think that means the compilation error applies to a different line, not the assignment that was shown.

edited Jan 9, 2013 at 15:56

answered Jan 9, 2013 at 15:32

Jonathan Leffler

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3 Comments

Jurgen Cuschieri Over a year ago

with the *prodname doesnt work. It seems to work without the *.

Jonathan Leffler Over a year ago

OK; then I don't understand where the compiler error was coming from. Without the * is what I first expected (it is the usual way of writing it), but I assumed that the assignment error applied to the assignment you showed. AFAICS, given your comment that *prodname does not work, the error can't apply to that line, but we don't have enough program to be sure.

Jurgen Cuschieri Over a year ago

btw I'm in C not in c++, Wes Miller

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