Primitive Data Types

Java - Basic Datatypes

There are two data types available in Java −

• Primitive Data Types
• Reference/Object Data Types

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.

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

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'