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
,boolean
andchar
- 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 type of a variable and the kind of values it can hold.
There are eight primitive data types in Java:
Data Type | Description |
---|---|
byte |
Stores whole numbers from -128 to 127 |
short |
Stores whole numbers from -32,768 to 32,767 |
int |
Stores whole numbers from -2,147,483,648 to 2,147,483,647 |
long |
Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807 |
float |
Stores fractional numbers. Sufficient for storing 6 to 7 decimal digits |
double |
Stores fractional numbers. Sufficient for storing 15 to 16 decimal digits |
boolean |
Stores true or false values |
char |
Stores a single character/letter or ASCII values |