How do I check how many elements are empty in an array?

Question

I am trying to save how many empty elements there are in an array. This is what I have done so far but it prints out that all lines are "not empty" which is wrong. How can I do this?

char arr[10][50]={NULL};
int lines;

//inserting values to arr

for(int i=0;i<10;i++){
   if(arr[i] == NULL){
       lines++;
       printf("empty");
   }
   else
       printf("not empty");
}

Answer 1

When you do arr[i] == NULL then arr[i] decays to a pointer to the first element of the array in arr[i] (i.e. &arr[i][0]), and that pointer will never be NULL.

I suspect you want e.g. something like arr[i][0] == '\0'.