very quick array question

[dobby156]

I am sure you get the gist of what I am trying to do; but if not I am trying to have an array of char potentially of different length, these are not user entered input or anything but declared at compile (hence why I am using arrays).

char[2][]charList;
charList[0] = new CharList{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' };
harList[1] = new CharList{ '+', '/', '-', '*', '=' };

this is not even attempt to compile; how should I write this.

thanks

[Bazzy]

http://www.cplusplus.com/forum/articles/7459/

[tummychow]

You use the new operator. Dynamically allocate the char arrays.
Waitaminnit - you're already doing that, where's your class implementation?

[Disch]

If you must use char arrays:

char charList[2][] = { "0123456789", "+/-*=" };

[tummychow]

You'd probably be better off with an array of std::string anyway.

[dobby156]

thanks for the input just going to try that now.

this is not a string in anyway, i am looping through the array to for expression evaluation (from an ASCII input) so I see no reason to include an entire library for this situation.

thank you

[tummychow]

Why not? You won't be able to tell the difference in overhead and string is far more efficient and easier to use than char[]. And it still supports subscripting across characters.

[dobby156]

Sorry i just tried that and it would no compile
char charList[2][] = { "0123456789", "+/-*=" };

VS reported
array bounds overflow and missing subscript

thanks again

[tummychow]

EDIT: Never mind, I see what you tried.
Anyway, that should work. But I'm no cstring expert, as I said I prefer std::string. With that the code should be relatively simple, although I don't remember how to do construction with an array initializer list. Only if you must use char[] should you really use it for this, you should be fine without.

[ronbtom]

I think the problem is with the empty subscript. You have charList[2][].
Make it charList[2][10]. This will leave unknown values in your second row after your entry =.

[tummychow]

Technically it should be able to determine the second subscript from the number of elements in the initializer list.
@OP: did you read the article Bazzy directed you to? It's the MD array article; it may have some tips or suggestions for this problem.
EDIT: Whoa, there are two MD articles on this forum! I never knew... OP, Disch's article on MD array pitfalls may also come in handy then, since that one explains how to engender them:
http://www.cplusplus.com/forum/articles/17108/

[dobby156]

If I get this right the real problem here is that C++ does like declaring an arrays of arrays with different depths?

so would it be better to create an array ([2]) of char*

if so how the hell would i go about that. as I said this is not to form a string but an actual list of chars: so if I can help from including string and vectors that would be great

[poet]

the solution is

char* charList[] = {"0123456789","+/-*="};

with this declaration you are able to loop through the array, e.g.,

charList[0][0] = '0';
charList[0][1] = '1';
charList[0][2] = '2';

and

charList[1][0] = '+';
charList[1][1] = '/';
charList[1][2] = '-';

[dobby156]

best! that worked

I might post my listing for the method up later so you can glance over it and see if it done correctly.