Data types

 Data Types in JAVA

• It is a type of data which is used in the program.
• There are many predefined data types in java library like int,char,float etc.

There are two types of data types 

1 .  Primitive Data type

2.  Non- Primitive Data Type

    

Primitive Data Type

• The data type which is predefined in the library is called primitive data type.
• It is named by a keyword for example int,float,char etc.
• There are eight primitive data types in java.
  byte, short, int, long, float, double, boolean and char.

     Primitive number types are divided into two groups:

Integer types stores whole numbers, positive or negative (such as 123 or -456), without decimals. Valid types are byte, short, int and long. Which type you should use, depends on the numeric value.

Floating point types represents numbers with a fractional part, containing one or more decimals. There are two types: float and double.

Integer Type

Type	Size in bytes	Range
byte	1	-128 to 127
short	2	-32,768 to 32,767
int	4	-2,147,483,648 to 2,147,483,647
long	8	-9,223,372,036,854,775,808 to 9,223.372,036,854,775,807

Float Type

You should use a floating point type whenever you need a number with a decimal, such as 9.99 or 3.14515.

The float and double data types can store fractional numbers. Note that you should end the value with an "f" for floats and "d" for doubles

Type	Size in bytes
float	4
double	8

Boolean

Very often in programming, you will need a data type that can only have one of two values, like:

• YES / NO
• ON / OFF
• TRUE / FALSE

For this, Java has a boolean data type, which can only take the values true or false

Keyword	boolean
Syntax	boolean x;
Value	True/False
Default	False

Character

The char data type is used to store a single character. The character must be surrounded by single quotes, like 'A' or 'c':

Keyword	char
Syntax	char x;
Value	'a','@','9'

Non-primitive Data Type

• The data type which is created by a programmer is called non-primitive data type.
• Non-primitive types can be used to call methods to perform certain operations.
• A primitive type starts with a lowercase letter, while non-primitive types starts with an uppercase letter.
• Example:class,interface,Arrays,String etc