Java Data Types

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Java programming language is a “strongly” typed language. Every variable declared must have a data type that determines the size of the variable in memory.

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Expressions in Java have types. Although data types are strictly defined, there is compatibility between certain data types. This allows type conversion and casting of variables.

The data types are

• Integers
• Floating-point numbers
• Characters
• Boolean

Main Type	Data Type	Size (in bits)	Range
Integer	Long   Int Short Byte	64   32 16 8	-9,223,372,036,854,775,808 to 9,223,372,036,854,775,807   -2,147,483,648 to 2,147,483,647 -32,768 to 32767 -128 to 127
Floating-point number	Double   Float	64   32	4.9e-324 to 1.8e+308   1.4e-045 to 3.4e+038
Character	Char	16	0 to 65536
Boolean	Boolean	8

Long

As per the table above, the long type is 64-bit signed type with a large range. The int type is the first choice for an integer type, but the long type is chosen when the number cannot be stored with int type.

long distance;

Int

The int type is the most common type used as an integer type. The int type is signed 32-bit type. Here is an example of int type.

int area;

short

The short type is the least used type in Java. It is signed 16-bit type with range -32,768 to 32767/ Here is an example of short type.

short total;

byte

The byte type is smallest of the integer type. It is signed 8-bit type suitable to store raw binary data. Other than that byte type can handle a stream of information from network, or file.

byte queue;

double

The double precision is also known as.double It has a storage of 64-bit. Also, it is faster in some optimized processors when compared to single precision. To maintain the accuracy of mathematical calculations, built-in functions like sin(), cos(), etc returns.double Here are some examples of.double

double radius;
double PI;

float

The float is a single precision that use32-bit of storage. Here are some examples of the.float

float length;
float height;

char

The char type is unsigned 16-bit to store Unicode characters. It has a range of 0 to 65536. The character is expressed in many ways.

• Using single quotes.
• Escape sequence
• Unicode escape sequence

Here is the example for each type.

Example #1

char answer = 'Y';
char day = 'f';

The escape sequence does work for all characters, but only a few. Here is the list.

Example #2

char ret = '\r';
char nwline = '\n';

Example #3

char a1 = '\u0041';    //The code '\u0041' is same as 'A'

Boolean

The boolean type has two values called boolean literals. Here are some examples of boolean type.

boolean finished = true;
boolean off;
off = false;

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