Variables

Variables are used whenever there’s a need to store a piece of data. A variable contains data that can be used in the program elsewhere. Using variables also ensures code re-usability since it can be used to replace the same value in multiple places.

Declaring a Variable

To declare a variable in Java, any of these three keywords can be used along with a variable name:

• The data type.
• The variable name.
• The value.

int age = 28;
char grade = 'A';
boolean late = true;
byte b = 20;
long num1 = 1234567;
short no = 10;
float k = (float)12.5;
double pi = 3.14;

The equal sign = is used to assign a value to a variable. After the initial assignment is made, the value of a variable can be updated to new values as needed.