How to assign a char an int value?

Question

I'm trying to make a solitaire game using structs and linked lists, I've started with reading cards from a file with colours and it's values, so I have a problem with such cards as 'A', 'J', 'D', 'K' their values are to be set to 1, 11, 12, 13 respectively. How do I do this in case of using following construction:

    #define J 11

    typedef struct card {
    char color[15];
    unsigned int value;
    struct card* pnext;
    struct card* pprev;
} cardsStruct;

struct card* pstart = NULL;
struct card* plast = NULL;

int main()
{
    FILE *myFile;
    cardsStruct card;
    if ((myFile = fopen("Cards.txt", "rb")) == NULL)
        return -1;
    while (!feof(myFile)){
        fscanf(myFile, "%s %u", card.color, &card.value);
        printf("%s %u\n", card.color, card.value);
    }
    fclose(myFile);
    return 0;
}

Any number in decimal or hexadecimal. You can define them as macros. — purec, Dec 20 '18 at 08:50
See second answer there as you have a lots issues here https://stackoverflow.com/questions/tagged/c?sort=frequent&pageSize=15 — 0___________, Dec 20 '18 at 08:52
Couple different approaches you could take. You could have `char face[10];` and `unsigned int pts;` - that's probably the easiest. Then treat every read and write as text. — torstenvl, Dec 20 '18 at 08:53
If you mean something like #define A 2, it doesn't work here — James Toaster, Dec 20 '18 at 08:53
You will want to look at [**Why is while ( !feof (file) ) always wrong?**](http://stackoverflow.com/questions/5431941/why-is-while-feof-file-always-wrong). — David C. Rankin, Dec 20 '18 at 08:55
Well, you cant use char for representation, I mean not 6 but '6' etc. Then no problems with 'K', 'A', etc. — purec, Dec 20 '18 at 09:02
You write, that you have a problem there. However, to me, it is not quite clear what problem you are actually asking about. Can you clarify this? — moooeeeep, Dec 20 '18 at 09:05
The problem is that I can't find a way to assign to, for example, 'J' card an int value of '11' — James Toaster, Dec 20 '18 at 09:07

Ruks · Answer 1 · 2018-12-20T09:08:57.890

0

In C, you can try to simulate the feel of maps from C++...

int characters[128] = {0};
characters['A'] = 1;
characters['J'] = 11;
characters['D'] = 12;
characters['K'] = 13;

And print it like this:

printf("%s %u\n", card.color, characters['K']);

edited Dec 20 '18 at 09:08

answered Dec 20 '18 at 08:55

Ruks

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You've specifically not initialized the array, so other characters will contain garbage now – Antti Haapala -- Слава Україні Dec 20 '18 at 08:59

score 0 · Answer 2 · answered Dec 20 '18 at 08:55

0

you need three forms of holding the cards:

In the text file
for program use
When displaying

I think the trick here is to do conversions. For example, in the file it is nicer to use letters (A,J,D/Q,K) so it will be human readable and also easy to edit. when displaying, you want it also to be human readable. In RAM, for program use, you better use an hexadecimal values so it will be easy to do calculations.

answered Dec 20 '18 at 08:55

eyalm

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Yeah, the cards will be held in the text file as for example "RED J", the rules are as in classic solitaire, where you can only put a card on acard with a value bigger by 1, for example "3 on 4", "10 on J", to make this possible I need to make 'J' into '11' – James Toaster Dec 20 '18 at 09:03
No, not only in printing I'm going to use 'J' for user input command like "move red J to 4" and then it should compare card's value with the last card in fourth stack, whether the difference is 1 or not, how would it compare J to 10? – James Toaster Dec 20 '18 at 10:21

score 0 · Answer 3 · answered Dec 20 '18 at 09:30

0

switch(card)
{
  case 'A':
     value = 1;
     break;
  case 'J':
     value = 11;
     break;
  /* ... */
}

answered Dec 20 '18 at 09:30

0___________

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moooeeeep · Answer 4 · 2018-12-20T10:47:24.190

In a comment you wrote:

the cards will be held in the text file as for example "RED J"

Obviously, you can't parse a letter with a format specifier for an unsigned integer.

So this is wrong:

fscanf(myFile, "%s %u", card.color, &card.value);

I suggest you read the file line wise (using fgets() or getline()), and try to parse it afterwards, e.g. using sscanf(). So if this fails to parse the number sscanf(in, "%14s %u", out), you can try to parse "%14s %c" afterwards.

A few other suggestions:

Don't mix the implementation of the linked list and the data type.
Define a different type to hold the list, than to represent the list node.
Split functionality in functions, especially taking input and parsing input.
Check and handle errors consistently.
Decouple the file representation of a card and the data representation in your program.
Create a function for deserialization, i.e., to convert the suit and rank strings to enum values or defined integer literals.
Create a function to convert suit to color, instead of storing a color string directly.
If you are new to C, then maybe it makes sense to work out the business logic in another simpler language first and then port it to C.

For reference and further reading:

How to assign a char an int value?

4 Answers4