...

<sscce>
class NullInteger {
 public static void main(String[] args) {
   Integer[] allInt = new Integer[10];
   for (int ii=0; ii< allInt.length; ii++) {
     System.out.println(
       "index " + ii + " \tvalue: " + allInt[ii] );
   }
   for (int ii=0; ii< allInt.length; ii+=3) {
     allInt[ii] = new Integer(ii+1);
   }
   for (int ii=0; ii< allInt.length; ii++) {
     System.out.println(
       "index " + ii + " \tvalue: " + (allInt[ii]==null) );
   }
 }
}
</sscce>

HTH

Andrew T.

1. If the integers have an out-of-bound value, initialize them to that
first. For example, if the values you set are all non-negative,
initialize to -1. If they must be positive, just check for myVar[10]==0.

2. Use Integer and check for null, As Andrew suggested.

3. Use a separate boolean array, the same length, and set the boolean at
an index to true when you set the int with the same index.

4. Structure your logic so that you only attempt to set each element once.

Patricia