Picture of an Array

An array is an object that is used to store a list of values. It is made out of a contiguous block of memory that is divided into a number of "slots." Each slot holds a value, and all the values are of the same type. In the example array at right, each slot holds an int.

The name of this array is data. The slots are indexed 0 through 9. Each slot can be accessed by using its index. For example, data[0] is the slot which is indexed by zero (which contains the value 23). data[5] is the slot which is indexed by 5 (which contains the value 14).

Facts:

• The slots are numbered sequentially starting at zero.
• If there are N slots in an array, the indexes will be 0 through N-1.

Sometimes the index is called a subscript. The expression data[5] is usually pronounced "data-sub-five" as if it were an expression from mathematics: data5.