Java Data Types
Java Data Types
As explained in the previous chapter, a variable in Java must be a specified data type:
Example
int myNum = 5;               // Integer (whole number)
float myFloatNum = 5.99f;    // Floating point number
char myLetter = 'D';         // Character
boolean myBool = true;       // Boolean
String myText = "Hello";     // String
Data types are divided into two groups:
- Primitive data types - includes 
byte,short,int,long,float,double,booleanandchar - Non-primitive data types - such as 
String, Arrays and Classes (you will learn more about these in a later chapter) 
Primitive Data Types
A primitive data type specifies the size and type of variable values, and it has no additional methods.
There are eight primitive data types in Java:
| Data Type | Size | Description | 
|---|---|---|
byte | 
1 byte | Stores whole numbers from -128 to 127 | 
short | 
2 bytes | Stores whole numbers from -32,768 to 32,767 | 
int | 
4 bytes | Stores whole numbers from -2,147,483,648 to 2,147,483,647 | 
long | 
8 bytes | Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 | 
float | 
4 bytes | Stores fractional numbers. Sufficient for storing 6 to 7 decimal digits | 
double | 
8 bytes | Stores fractional numbers. Sufficient for storing 15 decimal digits | 
boolean | 
1 bit | Stores true or false values | 
char | 
2 bytes | Stores a single character/letter or ASCII values | 
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