Data Types in Java

Data types specify the different sizes and values that can be stored in the variable. There are two types of data types in Java:

1. Primitive data types: The primitive data types include boolean, char, byte, short, int, long, float and double.
2. Non-primitive data types: The non-primitive data types include Classes, Interfaces, and Arrays.
   
   

   Primitive Data Types

   There are eight primitive datatypes supported by Java. Primitive datatypes are predefined by the language and named by a keyword. Let us now look into the eight primitive data types in detail.

   boolean

   • boolean data type represents one bit of information
   • There are only two possible values: true and false
   • This data type is used for simple flags that track true/false conditions
   • Default value is false
   • Example: boolean one = true

   char

   • char data type is a single 16-bit Unicode character
   • Minimum value is '\u0000' (or 0)
   • Maximum value is '\uffff' (or 65,535 inclusive)
   • Char data type is used to store any character
   • Example: char letterA = 'A'

   byte

   • Byte data type is an 8-bit signed two's complement integer

   • Minimum value is -128 (-2^7)

   • Maximum value is 127 (inclusive)(2^7 -1)

   • Default value is 0

   • Byte data type is used to save space in large arrays, mainly in place of integers, since a byte is four times smaller than an integer.

   • Example: byte a = 100, byte b = -50

   short

   • Short data type is a 16-bit signed two's complement integer

   • Minimum value is -32,768 (-2^15)

   • Maximum value is 32,767 (inclusive) (2^15 -1)

   • Short data type can also be used to save memory as byte data type. A short is 2 times smaller than an integer

   • Default value is 0.

   • Example: short s = 10000, short r = -20000

   int

   • Int data type is a 32-bit signed two's complement integer.

   • Minimum value is - 2,147,483,648 (-2^31)

   • Maximum value is 2,147,483,647(inclusive) (2^31 -1)

   • Integer is generally used as the default data type for integral values unless there is a concern about memory.

   • The default value is 0

   • Example: int a = 100000, int b = -200000

   long

   • Long data type is a 64-bit signed two's complement integer
   • Minimum value is -9,223,372,036,854,775,808(-2^63)
   • Maximum value is 9,223,372,036,854,775,807 (inclusive)(2^63 -1)
   • This type is used when a wider range than int is needed
   • Default value is 0L
   • Example: long a = 100000L, long b = -200000L

   float

   • Float data type is a single-precision 32-bit IEEE 754 floating point

   • Float is mainly used to save memory in large arrays of floating point numbers

   • Default value is 0.0f

   • Float data type is never used for precise values such as currency

   • Example: float f1 = 234.5f

   double

   • double data type is a double-precision 64-bit IEEE 754 floating point

   • This data type is generally used as the default data type for decimal values, generally the default choice

   • Double data type should never be used for precise values such as currency

   • Default value is 0.0d

   • Example: double d1 = 123.4