#include <acknex.h> 
#include <default.c>

void main()
{
   // allocate memory for 100 integers
   int *array = (int *)malloc(100 * sizeof(int));
	
   // initialize memory
   memset(array, 0, 100 * sizeof(int));
	
   // display int #3 on the screen (should be zero, but isn't)
   error(str_for_num(NULL, *(array + 2)));
} 

int array[100];

for(int iCurrentIndex = 0 ; iCurrentIndex < 100 ; iCurrentIndex++)
array[iCurrentIndex] = 0;

int *array = (int *)malloc(100 * sizeof(int));

int *array = (int *)malloc((int)sizeof(int) * 100);

or if you wanted floats use
float *array = (float *)malloc((int)sizeof(float) * 100);

// presumption: array length: 50, type: int

// initialize second half of array to zero
memset(array + 25, 0, 24 * 4);
// memset(&array[25], 0, 24 * 4); // alternative way