ARRAYS - Java Programming: From Problem Analysis to Program Design - page 555

To save space, we also draw an array, as shown in Figures 9-2(a) and 9-2(b).

[0] [1] [2] [3] [4]

num[0] num[1] num[2] num[3] num[4] num

num

0 0 0 0 0

0 0 0 0 0

( a ) (b)

FIGURE 9-2 Array num

Alternate Ways to Declare an Array
Java allows you to declare arrays as follows:

int list[]; //Line 1

Here, the operator [] appears after the identifier list , not after the data type int .
You should be careful when declaring arrays as in Line 1. Consider the following statements:

int alpha[], beta; //Line 2

int [] gamma, delta; //Line 3

The statement in Line 2 declares the variables alpha and beta . Similarly, the statement
in Line 3 declares the variables gamma and delta . However, the statement in Line 2
declares only alpha to be an array reference variable, while the variable beta is an int
variable. On the other hand, the statement in Line 3 declares both gamma and delta to
be array reference variables.
Traditionally, Java programmers declare arrays as shown in Line 3. We recommend that
you do the same.

9

Accessing Array Elements
The general form (syntax) used to access an array element is:

arrayName[indexExp]

where indexExp , called the index, is an expression whose value is a nonnegative integer
less than the size of the array. The index value specifies the position of the element in the
array. In Java, the array index starts at 0 .
In Java, [] is an operator called the array subscripting operator.