The array size (or length) is simply a count of its elements.

This is the heart and soul of arrays -- indexes. It's how we navigate and access them.

The indexes are "zero-based" which means:

• The start of the array is 0
• The end of the array is (size()-1) or (length-1)

Just another example here to show that we may "picture" arrays as left to right or top to bottom. This is just for "visualization" -- whichever you prefer.

We say that arrays are indexable. That means we can access elements at an index.

A couple of common ways to get array elements:

• elem = anArray[4]
• elem = anArray.get(4)

Similar to "getting", we can also set elements at specified indexes.

A couple of common ways to set array elements:

• anArray[4] = newElem
• anArray.set(4, newElem)

We can easily use loops to iterate over the array elements.

Here we traverse from the start to the end, e.g. indexes 0 to (length-1)

We can just as easily flip that around and traverse from the last index to the first index -- i.e. from index (length-1) to index 0.