Java – Basic Datatypes

Java,Variables are not anything but reserved reminiscence locations to keep values. This way that when you create a variable you reserve some space inside the memory.

Based at the information type of a variable, the working machine allocates reminiscence and decides what can be saved within the reserved memory. Therefore, via assigning one of a kind records kinds to variables, you can shop integers, decimals, or characters in those variables.

There are information types to be had in Java −

  • Primitive Data Types
  • Reference/Object Data Types

Java,Primitive Data Types

There are eight primitive datatypes supported by way of Java. Primitive datatypes are predefined through the language and named via a key-word. Let us now investigate the eight primitive statistics sorts in element.


  • 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 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 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 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


  • This 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 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 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 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’

Java,Reference Datatypes

  • Reference variables are created the use of defined constructors of the training. They are used to get entry to gadgets. These variables are declared to be of a specific type that can not be modified. For example, Employee, Puppy, etc.
  • Class items and diverse sort of array variables come below reference datatype.
  • Default price of any reference variable is null.
  • A reference variable may be used to refer any item of the declared kind or any like minded type.
  • Example: Animal animal = new Animal(“giraffe”)

Java Literals

A literal is a source code illustration of a set price. They are represented without delay within the code without any computation.

Literals may be assigned to any primitive type variable. For example −

byte a = 68; char a = ‘A’;

Byte, int, lengthy, and quick may be expressed in decimal(base 10), hexadecimal(base 16) or octal(base eight) range systems as well.

Prefix 0 is used to indicate octal, and prefix 0x indicates hexadecimal when the usage of those quantity structures for literals. For instance −

int decimal = 100; int octal = 0144; int hexa = 0x64;

String literals in Java are unique like they’re in most other languages through enclosing a chain of characters among a pair of double costs. Examples of string literals are −


“Hello World” “two\nlines” “\”This is in quotes\””

String and char sorts of literals can incorporate any Unicode characters. For example −

char a = ‘\u0001’; String a = “\u0001”;

Java language supports few special escape sequences for String and char literals as nicely. They are −

Notation Character represented
\n Newline (0x0a)
\r Carriage return (0x0d)
\f Formfeed (0x0c)
\b Backspace (0x08)
\s Space (0x20)
\t tab
\” Double quote
\’ Single quote
\\ backslash
\ddd Octal character (ddd)
\uxxxx Hexadecimal UNICODE character (xxxx)