Arrays objects are basically a single public variable length .which is gives us the no of elements in the array.The last index values always less than the length .
Its basic formula that :
Value of last index = length - 1 .
for the example if the length of an array is 4 then the index value are 0 to 3 .
Animal myAnimal = new Animal; // creates an array of 6 Animal references
for (int x = 0; x < myAnimal.length; x++)
myAnimals[x] = new Animal(); // assign a new Animal to the index position x
The Length variables signifies basically how many elements the array holds,but its not signifies those elements have been initialized.