Data Types in Java | Crystal Academy

Data Types in Java

written by Sanjay Nair

Data Types in Java

There are majorly two types of languages.
First one is Statically typed language where each variable and expression type is already known at compile time.
Once a variable is declared to be of a certain data type, it cannot hold values of other data types.
Java is statically typed and also a strongly typed language because in Java, each type of data (such as integer, character, hexadecimal, packed decimal, and so forth) is predefined as part of the programming language and all constants or variables defined for a given program must be described with one of the data types.

Java has two categories of data:

Primitive data (e.g., number, character)
Object data (programmer created types)

Primitive data

Primitive data are only single values; they have no special capabilities.
There are 8 primitive data types

Data Type	Size(bytes)
boolean	1
int	4
short	2
byte	1
long	8
float	4
double	8
char	2

boolean

boolean data type represents only one bit of information either true or false .
Values of type boolean are not converted implicitly or explicitly (with casts) to any other type.

byte

The byte data type is an 8-bit signed two’s complement integer.The byte data type is useful for saving memory in large arrays.
Size: 8-bit
Value: -128 to 127

short

The short data type is a 16-bit signed two’s complement integer. Similar to byte, use a short to save memory in large arrays, in situations where the memory savings actually matters.
Size: 16 bit
Value: -32,768 to 32,767 (inclusive)

int

It is a 32-bit signed two’s complement integer.
Size: 32 bit
Value: -231 to 231-1

long:

The long data type is a 64-bit two’s complement integer.
Size: 64 bit
Value: -263 to 263-1.

Floating point Numbers : float and double

float

The float data type is a single-precision 32-bit IEEE 754 floating point. Use a float (instead of double) if you need to save memory in large arrays of floating point numbers.
Size: 32 bits
Suffix : F/f Example: 9.8f

double:

The double data type is a double-precision 64-bit IEEE 754 floating point. For decimal values, this data type is generally the default choice.

char

The char data type is a single 16-bit Unicode character. A char is a single character.

A Sample Java Program to demonstrate the primitive data types

class DataTypes
{
	public static void main(String args[])
	{

		// declaring character

		char a = 'G';

		// Integer data type is generally

		// used for numeric values

		int i=89;

		// use byte and short if memory is a constraint

		byte b = 4;

		// this will give error as number is

		// larger than byte range

		// byte b1 = 7888888955;


		short s = 56;

		// this will give error as number is

		// larger than short range

		// short s1 = 87878787878;


		// by default fraction value is double in java

		double d = 4.355453532;

		// for float use 'f' as suffix

		float f = 4.7333434f;

		System.out.println("char: " + a);
		System.out.println("integer: " + i);
		System.out.println("byte: " + b);
		System.out.println("short: " + s);
		System.out.println("float: " + f);
		System.out.println("double: " + d);
	}
}

class DataTypes

{

public static void main(String args[])

{

// declaring character

char a = 'G';

// Integer data type is generally

// used for numeric values

int i=89;

// use byte and short if memory is a constraint

byte b = 4;

// this will give error as number is

// larger than byte range

// byte b1 = 7888888955;

short s = 56;

// this will give error as number is

// larger than short range

// short s1 = 87878787878;

// by default fraction value is double in java

double d = 4.355453532;

// for float use 'f' as suffix

float f = 4.7333434f;

System.out.println("char: " + a);

System.out.println("integer: " + i);

System.out.println("byte: " + b);

System.out.println("short: " + s);

System.out.println("float: " + f);

System.out.println("double: " + d);

}

Output

char: G

integer: 89

byte: 4

short: 56

float: 4.7333436

double: 4.355453532

December 25, 2017 0 comment