Chapter 7, Problem 4SA

Program Plan Intro

Array:

An array is defined as a group that consists of similar data types.

• The array size must be specified by an “int” value and not long or short.
• In Java, all arrays are allocated dynamically.
• An array is always indexed, starting from 0.

Declaring an array reference and creating an array:

• To insert elements to an array, first an array has to be created by using new operator and then the reference variable is assigned.
• The syntax is as follows,

arrayRefVar = new elementType[arraySize]

• From the above statement it is clear that, an array is created using new elementType[arraySize] and then the reference to the newly created array is assigned to the variable arrayRefVar.
• It is possible to declare an array variable, create an array and assign the reference to a variable in a single statement itself.

The syntax will be as follows,

elementType[]arrayRefVar = new elementType[arraySize];

elementType arrayRefVar[]= new elementType[arraySize);

Example:

double myFile = new double[20];

The statement given above declares an array variable myFile and then creates an array that consists of 20 elements which are of the datatype double and at last assign the reference to myFile.