How to get elements of an array that is not null

Question

I am doing gift (String-type) storage, using arrays, with the maximum 500 million. I want to get the number of used elements in an array like how many gifts are currently in sto

Answer 1

You can iterate through the array and count the initialized array elements.

int counter = 0;
for (int i = 0; i < arrayName.length; i ++)
    if (arrayName[i] != null)
        counter ++;

Also it would be even better if you used ArrayList so you could use size()

ArrayList arrayName = new ArrayList(20);
System.out.println(arrayName.size());

It will print 0, as there are no elements added to the ArrayList.