CODEWITHSUNDEEP
csegmentation-fault
L_Cleo
L_Cleo

Reputation: 1527

Segmentation Fault on Simple Function

I keep getting a segmentation fault 11 when I call this function

    void flexibleArray(int *array, int *length) {
    int cnt = 0, number = 0;
    while (number!=-1) {
        printf("\nInsert the variable :"); scanf("%d", &number);
        if (number!=-1){
            cnt++;
            array = realloc(array, cnt * sizeof(int));
            array[cnt-1] = number;
        }
    }
    *length = cnt;
}

as 

int *array = NULL, arrayLength;
flexibleArray(array, &arrayLength);

It's a really simple function that I've always used and I don't get why is it giving me this error right now. I've been playing with it around to try to nail down the line that's giving me the problem, and I found out that taking off the *length = cnt; line apparently doesn't give me the problem. Can I avoid the error keeping that line? Thanks

CORRECT CODE:

   int* flexibleArray(int *length) {
    int *flexArray = NULL;
    int cnt = 0, number = 0;
    while (number!=-1) {
        printf("\nInsert the variable :"); scanf("%d", &number);
        if (number!=-1){
            cnt++;
            flexArray = realloc(flexArray, cnt * sizeof(int));
            flexArray[cnt-1] = number;
        }
    }
    *length = cnt;
    return flexArray;
}

and in main()

int *array = NULL, arrayLength;
array = flexibleArray(&arrayLength);

Upvotes: 0

Views: 82

Answers (1)

kiran Biradar
kiran Biradar

Reputation: 12742

as a pointer initialised to null, while arrayLength is just defined as int and not initialised

In that case you need to pass its reference to function.

flexibleArray(&array, &arrayLength);

And function will become

void flexibleArray(int **array, int *length) {
    int cnt = 0, number = 0;
    while (number!=-1) {
        printf("\nInsert the variable :"); scanf("%d", &number);
        if (number!=-1){
            cnt++;
            *array = realloc(*array, cnt * sizeof(int));
            (*array)[cnt-1] = number;
        }
    }
    *length = cnt;
}

Or

return new pointer from the function.

int *flexibleArray(int *array, int *length)
{
  ....
  return array;
}

from main

array = flexibleArray(array, &arrayLength);

Upvotes: 6

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