Declaring and Initializing Variables in Java

A variable must be declared before it can be initialized with a value. The general syntax of variable declarations is:

• data_type variableName;

For example:

• int number;
• char ch;

Variables can be declared in a class outside of any methods or inside of a method. Variables can also be declared and initialized in one line. The following example code illustrates these aspects of variable declaration and initialization.

Code Sample 3-1

Note that multiple variables can be declared on one line. Initialization is done using the assignment operator (=). Initialization can occur at declaration time or later in the program. The variable sum was declared and used in the same line.

Where variables are declared is a matter of programming style and need since this determines how and where they can be used.