CODEWITHSUNDEEP
arrayscgdb
ccc31807
ccc31807

Reputation: 773

C array, why does each element contain the same value?

Below is an MRE and the OUTPUT (truncated). When I use gdb, I confirm that each element of my deck array contains each individual card. However, when I iterate through the deck array, all the cards are the Ace of Spades. Why? I've attempted due diligence. The program compiles and runs. The logic seems correct.

COMPILE

gcc -g prog33.c -o prog33.exe -Wall

MRE

//includes
#include <stdio.h>
#define DECK 52

//variable and function declarations
enum suit { clubs, diamonds, hearts, spades }; 
enum value { two, three, four, five, six, seven, eight, nine, ten, jack, queen, king, ace };
char *Suit[] = {"Clubs","Diamonds","Hearts","Spades" };
char *Values[] = {"Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten","Jack","Queen","King","Ace" };
char  *deck[DECK];
char mycard[20];

//main function
int main(int argc, char *argv[])
{
    printf("prog33.c, enums\n");

    for(int s = clubs; s <= spades; s++)
    {
        printf("%d. %s\n", s, Suit[s]);
        for(int v = two; v <= ace; v++)
        {
            int idx = (s*13) + v;
            sprintf(mycard, "%s of %s", Values[v], Suit[s]);
            printf("    %d, %s, %d, --- %s\n", v, Values[v], idx, mycard);
            deck[idx] = mycard;
            printf("        %i. %s\n", idx, deck[idx]);
        }
    }; 

    for(int i = 0; i < DECK; i++) printf("%d. %s\n", i, deck[i]);
    return 0;
}

OUTPUT (truncated)

    ...
    11, King, 24, --- King of Diamonds
        24. King of Diamonds
    12, Ace, 25, --- Ace of Diamonds
        25. Ace of Diamonds
2. Hearts
    0, Two, 26, --- Two of Hearts
        26. Two of Hearts
    1, Three, 27, --- Three of Hearts
        27. Three of Hearts
    2, Four, 28, --- Four of Hearts
        28. Four of Hearts
    3, Five, 29, --- Five of Hearts
        29. Five of Hearts
    4, Six, 30, --- Six of Hearts
        30. Six of Hearts
...
    21. Ace of Spades
    22. Ace of Spades
    23. Ace of Spades
    24. Ace of Spades
    25. Ace of Spades
    26. Ace of Spades
    27. Ace of Spades
    28. Ace of Spades
    29. Ace of Spades
    ...

Upvotes: 0

Views: 67

Answers (1)

Y.Jie
Y.Jie

Reputation: 152

Try it.You will find why.

#include <stdio.h>
#include <string.h>
#define DECK 52

//variable and function declarations
enum suit { clubs, diamonds, hearts, spades }; 
enum value { two, three, four, five, six, seven, eight, nine, ten, jack, queen, king, ace };
char *Suit[] = {"Clubs","Diamonds","Hearts","Spades" };
char *Values[] = {"Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten","Jack","Queen","King","Ace" };
char  deck[DECK][128];
char mycard[20];

//main function
int main(int argc, char *argv[])
{
    printf("prog33.c, enums\n");

    for(int s = clubs; s <= spades; s++)
    {
        printf("%d. %s\n", s, Suit[s]);
        for(int v = two; v <= ace; v++)
        {
            int idx = (s*13) + v;
            sprintf(mycard, "%s of %s", Values[v], Suit[s]);
            printf("    %d, %s, %d, --- %s\n", v, Values[v], idx, mycard);
            strcpy(deck[idx], mycard);
            printf("        %i. %s\n", idx, deck[idx]);
        }
    }; 

    for(int i = 0; i < DECK; i++) printf("%d. %s\n", i, deck[i]);
    return 0;
}

Upvotes: 2

Related Questions