C中的calloc结构

Question

I'm trying to initialize a pointer to a struct with 0.0 values in there. Look at the following situation:

typedef struct 
{
    float a;
    float b;
    float c;
} structA;

structA *ptr = calloc(100000, sizeof(structA));

I want all the values in *ptr be structA with initial values of {0.0, 0.0, 0.0}, but this is not I have now. Many of the indices of *ptr appear correctly, but some indices appear with weird values (like {0.0, 0.0, 10241256124.0}).

If I try malloc, the same thing happens.

What should I do?

Answer 1

You're doing something wrong... I've never used objective-c, so I stuck the code below into ideone.com and it worked as expected... (printing out done, not failed because) all values were zero'd. My guess is you're not checking properly, since it's quite unlikely there's a bug in your compiler...

#include <malloc.h>

typedef struct 
{
    float a;
        float b;
        float c;
} structA;



int main() {
    int count = 100000;
    int i;
    structA *ptr = calloc(count, sizeof(structA));
    if(ptr) {
        for(i=0;i<count;i++) {
            if(ptr[i].a || ptr[i].b || ptr[i].c) {
                printf("fail\n");
            }
        }
        printf("done\n");
    }
    return 0;
}