Data Types

Table of Contents

• Table Of Contents
• Basic Data Structure
• Wrapper Types
  • system diagram

Basic Data Structure

There are eight major data types in Java, which can be divided into numerical, character, and boolean types.

• Numerical Types

Data Type	Size	Ranges
byte	8 bit	-128 ~ 127
short	16 bit	-2^15 ~ 2^15 - 1
int	32 bit	-2^31 ~ 2^31 - 1
long	64 bit	-2^63 ~ 2^63 - 1
float	32 bit	single precision floating point type, such as 2.0f
double	64 bit	higher precision floating point type, such as 2.0

• Character Types

Data Type	Size	Ranges
char	16 bit	Used to represent Unicode characters, 1 character = 2 bytes

• Boolean Types

Data Type	Size	Ranges
boolean	logical value	true && false

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Wrapper Types

In Java, each primitive data type has a corresponding wrapper class. Assignment and conversion between the primitive types and their corresponding wrapper classes are achieved through automatic boxing and unboxing.

Primitive Data Types	Wrapper Classes
boolean	Boolean
char	Character
byte	Byte
short	Short
int	Integer
long	Long
float	Float
double	Double

1. Automatic Boxing refers to automatically converting a primitive value into its corresponding object wrapper.

2. Unboxing is the reverse process where an object wrapper's value is converted back to its corresponding primitive type.

system diagram