DATA TYPES

A Data type is the type of data that can be stored into the variable. A description on a variable

that determines what kind of information you can enter in the variable.

There are seven primitive data types, which are supported by Java language programming. A

primitive data type is a data type, which is predefined in Java. Following are the eight

The term “ Data Type” refers to the type of data that can be stored in a variable.

Java is sometimes called a “ strongly typed ” language.

Java has two types of data types.

1. Primitive data types.

2. Reference data types.

Primitive data types:

Primitive data types are the data types that are defined by the language Itself.

The memory location associated with a primitive types variables contains the actual value of

the variable.It is also called as Value types.

Java’s Primitive Types

Type Explanation

int A 32-bit (4-byte) integer value

short A 16-bit (2-byte) integer value

long A 64-bit (8-byte) integer value

byte An 8-bit (1-byte) integer value

float A 32-bit (4-byte) floating-point value

double A 64-bit (8-byte) floating-point value

char A 16-bit character using the Unicode encoding scheme

boolean A true or false value

primitive data types:

int

It is a 32-bit signed two's complement integer data type. It ranges from -2,147,483,648 to

2,147,483,647. This data type is used for integer values. However for wider range of values

use long.

byte

The byte data type is an 8-bit signed two's complement integer. It ranges from -128 to127

(inclusive). We can save memory in large arrays using byte. We can also use byte instead of

int to increase the limit of the code.

short

The short data type is a 16-bit signed two's complement integer. It ranges from -32,768 to

32,767. short is used to save memory in large arrays.

long

The long data type is a 64-bit signed two's complement integer. It ranges from -

9,223,372,036,854,775,808 to 9,223,372,036,854,775,807. Use this data type with larger

range of values.

float

The float data type is a single-precision 32-bit IEEE 754 floating point. It ranges from

1.40129846432481707e-45 to 3.40282346638528860e+38 (positive or negative). Use a float

(instead of double) to save memory in large arrays. We do not use this data type for the exact

values such as currency. For that we have to use java.math.BigDecimal class.

double

This data type is a double-precision 64-bit IEEE 754 floating point. It ranges from

4.94065645841246544e-324d to 1.79769313486231570e+308d (positive or negative). This

data type is generally the default choice for decimal values.

boolean

The boolean data type is 1-bit and has only two values: true and false. We use this data type

for conditional statements. true and false are not the same as True and False. They are defined

constants of the language.

char

The char data type is a single 16-bit, unsigned Unicode character. It ranges from 0 to 65,535.

They are not same as ints, shorts etc.

/* Program on Datatypes */

class datatypes

{

public static void main(String []args)

{

int a=457647657;

byte b=12;

short c=435;

long d=345;

float g=3.5f;

double f=345.6;

char k='a';

boolean h=false;

System.out.println("Integer="+a);

System.out.println("Byte="+b);

System.out.println("Short="+c);

System.out.println("Long="+d);

System.out.println("Float="+g);

System.out.println("Double="+f);

System.out.println("Character="+k);

if(h==true)

System.out.println("Boolean value is true");

else

System.out.println("Boolean value is false");

}

}

Output:

E:\sysvol>javac datatypes.java

E:\sysvol>java datatypes

Integer=457647657

Byte=12

Short=435

Long=345

Float=3.5

Double=345.6

Character=a

Boolean value is false

Reference data types :

Reference types are types that are defined by the language java API rather than by the

language itself.

• The memory location associated with a reference tpes variable contains an address

(called pointer) that indicates the memory location of the actual object.