two dimensional int array access problems ;/

[krST]

Hi again

I have a constant int array which looks like that:

const int *summaries[] = {{3, 4, 5, 6, 0}, {5, 0}};

i guess there is something wrong with it becasue when compiling i get such warnings:

quota_prepare.c:28: warning: braces around scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[0]')
quota_prepare.c:28: warning: initialization makes pointer from integer without a cast
quota_prepare.c:28: warning: excess elements in scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[0]')
quota_prepare.c:28: warning: excess elements in scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[0]')
quota_prepare.c:28: warning: excess elements in scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[0]')
quota_prepare.c:28: warning: excess elements in scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[0]')
quota_prepare.c:28: warning: braces around scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[1]')
quota_prepare.c:28: warning: initialization makes pointer from integer without a cast
quota_prepare.c:28: warning: excess elements in scalar initializer
quota_prepare.c:28: warning: (near initialization for `summaries[1]')

And when i try to access one of the fields i get segmentation fault.

Could You please tell me how to correct this?

Best regards

[quzah]

You don't have a two dimensional array there. You have an array of pointers to integers.


Quzah.

[ssharish2005]

it should be some thing like this

int arr[][10]={{3, 4, 5, 6, 0}, {5, 0}};

and here is a sample code on how to work on 2D array

#include<stdio.h>

int main()
{
    int arr[][10]={{3, 4, 5, 6, 0}, {5, 0}};
    int i,j;

    for(i=0;i<2;i++)
    {
        for(j=0;j<5;j++)
            printf("%d\t",arr[i][j]);
        
        printf("\n");
    }
    getchar();   
}
/*myoutput
3       4       5       6       0
5       0       0       0       0
*/

ssharish2005

[krST]

Hi

Thank You very much for this one ;] of course it works just fine.
But i have one more questions about multid. arrays. Is there any way of knowing what is the size of the first dimension? I need it for my while loop. I always put 0 on the end of the field to know where it ends but i don't know how many fields there are and after second pass i get segmentation fault. I can put there {0} and do

if (arr[i][0] == 0) break;

but i thought that maybe there is a better way.


Best regards

[cwr]

Well, you can do:

sizeof arr / sizeof arr[0]

To work out the number of rows, if that's what you mean.

[krST]

What i want is to get to know number x from array[x][y]

[ssharish2005]

What i want is to get to know number x from array[x][y]

look CWR post, to get the value of 'x' thats is no of rows.

ssharish2005