Primitive data types

 In Java, variables are used to store data values that can be manipulated by the program. There are several data types in Java, including:

Primitive data types:

byte: 8-bit integer

short: 16-bit integer

int: 32-bit integer

long: 64-bit integer

float: 32-bit floating-point number

double: 64-bit floating-point number

boolean: true/false value

char: single character

Non-primitive data types:

String: a sequence of characters

Arrays: a collection of similar data types

Classes: user-defined data types

To declare a variable in Java, you need to specify the data type and give it a name. For example:

int age = 27;

boolean isStudent = true;

double height = 1.75;

String name = "InfiniLearn";

In this example, we have declared four variables: age, isStudent, height, and name. The data types of the variables are int, boolean, double, and String, respectively. In Java, variable names are case-sensitive and must begin with a letter, underscore, or dollar sign.