CODEWITHSUNDEEP
cdynamic-arrays
Abdullah Obeid
Abdullah Obeid

Reputation: 74

Invalid operands to binary - (have 'int' and 'int *')

I've a problem when I run the program which is:

invalid operands to binary - (have 'int' and 'int *')

Since I defined a dynamic array **engelCikacagiYer then I tried to make an operation on karakterHP

int karakterHP = 100;

int **engelCikacagiYer;

engelCikacagiYer = malloc(engelSayisi * sizeof(int));

for(i = 0; i < engelSayisi; i++){
    engelCikacagiYer[i] = (rand() % (100 - 5 + 1) + 5);
}

for(i = parkurUzunlugu.Baslangic; i < parkurUzunlugu.Bitis; i++){
    if (asal(engelCikacagiYer)) {
        karakterHP -= engelCikacagiYer[i];
        printf("%d\t", karakterHP);
    }
}

Upvotes: 0

Views: 407

Answers (2)

user12211554
user12211554

Reputation:

Change int **engelCikacagiYer; to int *engelCikacagiYer;.

By your code it seems you want a dynamic array of ints, not a dynamic array of int pointers.

Upvotes: 2

anastaciu
anastaciu

Reputation: 23802

This piece of code:

int **engelCikacagiYer;

engelCikacagiYer = malloc(engelSayisi*sizeof(int));

Is not correct, to allocate memory to a double pointer, aka pointer to pointer you need to allocate using the size it points to and that is pointer to int so you would need:

engelCikacagiYer = malloc(engelSayisi*sizeof(int*));

Or better yet:

engelCikacagiYer = malloc(engelSayisi*sizeof(*engelCikacagiYer));

Later you try to assign an int value to a engelCikacagiYer[i] which is a pointer variable not an int variable, hence the error.

If you really need a double pointer, after the first malloc you will need to allocate memory for each engelCikacagiYer[i] pointer:

for(int i = 0; i < engelSayisi; i++){
    engelCikacagiYer[i] = malloc(sizeof(**engelCikacagiYer));
}

And assing values as if it was a 2D array (I mean using the same notation), example:

engelCikacagiYer[i][0] = (rand()%(100-5+1)+5);

or

*engelCikacagiYer[i] = (rand()%(100-5+1)+5);

Here is a simplified possible implementation of a correct allocation:

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int **engelCikacagiYer;

    engelCikacagiYer = malloc(100 * sizeof(*engelCikacagiYer)); //check allocation for errors

    for(int i = 0; i < 100; i++){
        engelCikacagiYer[i] = malloc(sizeof(**engelCikacagiYer)); //check allocation
        *engelCikacagiYer[i] = (rand() % (100 - 5 + 1) + 5);
    }

    for (int i = 0; i < 100; i++) //test print
    {
        printf("%d ", *engelCikacagiYer[i]);
    }
}

In any case, for the code you present using a single pointer to int would also be a valid (and simpler) solution.

Upvotes: 2

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