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Java Data Types

As discussed earlier, data type specifies the type of data which we are storing in a variable.

In Java, we can divide data types in two groups:

Primitive data types
Reference data types

Primitive Data Types

Data Type	Size	Description
byte	8 bits	Represents a signed 8-bit integer value. Range: -128 to 127.
short	16 bits	Represents a signed 16-bit integer value. Range: -32,768 to 32,767.
int	32 bits	Represents a signed 32-bit integer value. Range: -2^31 to 2^31-1.
long	64 bits	Represents a signed 64-bit integer value. Range: -2^63 to 2^63-1.
float	32 bits	Represents a single-precision floating-point number. It's used for decimal values. Example: 3.14159f.
double	64 bits	Represents a double-precision floating-point number. It's used for decimal values. Example: 3.14159.
char	16 bits	Represents a single Unicode character. Example: 'A', '1'.
boolean	1 bit	Represents a true or false value.

Reference Data Types

Data Type	Description
class	Represents user-defined types. Classes define objects and their behavior in Java.
interface	Represents a blueprint for classes. Interfaces define a set of methods that classes must implement.
enum	Represents a special type used to define a set of constants. Enums are often used for defining a limited set of values.
array	Represents a collection of elements of the same data type. Arrays can be of primitive or reference types.

We will not focus on the details of reference data types here.

String

Although it's not a primitive data type, String is widely used to represent text in Java. It's a class that provides methods for manipulating strings. We will discuss more about strings in strings section.

Variables with different Data Types

Scientific Numbers in Java

A floating point number can be used to store a scientific number with "e" corresponding to the power of 10.