Question

Say you have a program like this

#include <stdio.h>

int
main (void)
{
  char **foo;
  foo = malloc (100);
  foo[0] = "cat";
  foo[1] = "dog";
  foo[2] = "bird";
  return 0;
}

How could you iterate the array, for example printing all the elements, without hard coding the upper bound?

Answer 1

Since you want to do :

foo[0] = "cat";

which stores the address of string literal into the elements of array foo, each element of the array must be of type char pointer. But you are doing:

foo = malloc (100);

which makes each element of foo a char and not char pointer.

What you need it:

foo = malloc (100 * sizeof(char*));

To iterate over the filled elements of the array, you can keep an explicit counter equal to the number of elements filled