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Java - Basic DatatypesJava - Basic Datatypes
Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in the memory.Variables are nothing but reserved memory locations to store values. This means that when you create a variable you reserve some space in the memory. Based on the data type of a variable, the operating system allocates memory and decides what can be stored in the reserved memory. Therefore, by assigningBased on the data type of a variable, the operating system allocates memory and decides what can be stored in the reserved memory. Therefore, by assigning different data types to variables, you can store integers, decimals, or characters in these variables.different data types to variables, you can store integers, decimals, or characters in these variables. There are two data types available in Java −There are two data types available in Java − Primitive Data Types Primitive Data Types Reference/Object Data Types Reference/Object Data Types
Primitive Data TypesPrimitive 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 theThere 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.eight primitive data types in detail.
bytebyte
Byte data type is an 8-bit signed two's complement integer Byte data type is an 8-bit signed two's complement integer Minimum value is -128 (-2^7) Minimum value is -128 (-2^7) Maximum value is 127 (inclusive)(2^7 -1) Maximum value is 127 (inclusive)(2^7 -1) Default value is 0 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. 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 Example: byte a = 100, byte b = -
shortshort
Short data type is a 16-bit signed two's complement integer Short data type is a 16-bit signed two's complement integer Minimum value is -32,768 (-2^15) Minimum value is -32,768 (-2^15) Maximum value is 32,767 (inclusive) (2^15 -1) 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 integerShort 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. Default value is 0. Example: short Example: short s = 10000, short r = -20000s = 10000, short r = -
intint
Int data type is a 32-bit signed two's complement integer. Int data type is a 32-bit signed two's complement integer. Minimum value is - 2,147,483,648 (-2^31) Minimum value is - 2,147,483,648 (-2^31) Maximum value is 2,147,483,647(inclusive) (2^31 -1) 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. Integer is generally used as the default data type for integral values unless there is a concern about memory. The default value is 0 The default value is 0 Example: int a = 100000, int b = -200000 Example: int a = 100000, int b = -
longlong
Long data type is a 64-bit signed two's complement integer Long data type is a 64-bit signed two's complement integer Minimum value is -9,223,372,036,854,775,808(-2^63) 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) 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 This type is used when a wider range than int is needed Default value is 0L Default value is 0L Example: long a = 100000L, long b = -200000L Example: long a = 100000L, long b = -200000L
floatfloat
Float data type is a single-precision 32-bit IEEE 754 floating point 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 Float is mainly used to save memory in large arrays of floating point numbers Default value is 0.0f Default value is 0.0f Float data type is never used for precise values such as currency Float data type is never used for precise values such as currency Example: float f1 = 234.5f Example: float f1 = 234.5f
doubledouble
Java LiteralsJava Literals A literal is a source code representation of a fixed value. They are represented directly in the code without any computation.A literal is a source code representation of a fixed value. They are represented directly in the code without any computation. Literals can be assigned to any primitive type variable. For example −Literals can be assigned to any primitive type variable. For example − byte byte aa == 6868 ;; char char aa == 'A''A';; byte, int, long, and short can be expressed in decimal(base 10), hexadecimal(base 16) or octal(base 8) number systems as well.byte, int, long, and short can be expressed in decimal(base 10), hexadecimal(base 16) or octal(base 8) number systems as well. Prefix 0 is used to indicate octal, and prefix 0x indicates hexadecimal when using these number systems for literals. For example −Prefix 0 is used to indicate octal, and prefix 0x indicates hexadecimal when using these number systems for literals. For example − int int decimaldecimal == 100100 ;; int int octaloctal == 01440144 ;; int int hexahexa (^) == 0x640x64;; String literals in Java are specified like they are in most other languages by enclosing a sequence of characters between a pair of double quotes. Examples ofString literals in Java are specified like they are in most other languages by enclosing a sequence of characters between a pair of double quotes. Examples of string literals are −string literals are −
ExampleExample
"Hello World" "Hello World" "two\nlines" "two\nlines" ""This is in quotes"" ""This is in quotes"" String and char types of literals can contain any Unicode characters. For example −String and char types of literals can contain any Unicode characters. For example − char char aa == (^) '\u0001''\u0001';; String String aa (^) == "\u0001""\u0001";; Java language supports few special escape sequences for String and char literals as well. They are −Java language supports few special escape sequences for String and char literals as well. They are −
NotationNotation^ Character representedCharacter represented \n\n^ Newline (0x0a)Newline (0x0a) \r\r^ Carriage return (0x0d)Carriage return (0x0d) \f \f Formfeed (0x0c)Formfeed (0x0c) \b\b^ Backspace (0x08)Backspace (0x08) \s \s Space (0x20)Space (0x20) \t \t tabtab "" Double quoteDouble quote ' ' Single quoteSingle quote \ \ backslashbackslash \ddd \ddd Octal character (ddd)Octal character (ddd) \uxxxx\uxxxx^ Hexadecimal UNICODE character (xxxx)Hexadecimal UNICODE character (xxxx) What is Next?What is Next? This chapter explained the various data types. The next topic explains different variable types and their usage. This will give you a good understanding on howThis chapter explained the various data types. The next topic explains different variable types and their usage. This will give you a good understanding on how they can be used in the Java classes, interfaces, etc.they can be used in the Java classes, interfaces, etc.
