JAVA DATA TYPES

JAVA Data Types

A data type in programming is a classification that specifies which type of value a variable can hold, what type of operations can be performed on those values, and how those values are stored in memory

Types Of Datatype:

•  Primitive data types - includes byte, short, int, long, float, double and boolean, etc...

•  Non-primitive data types - such as String, Arrays and Classes

Data Type	Size
byte	1 byte
short	2 bytes
int	4 bytes
long	8 bytes
float	4 bytes
double	8 bytes
Boolean	1 bit
char	2 bytes

Primitive Data Types

A primitive data type in Java defines the type of a variable and the values it can store. Java has eight primitive data types:

1. Byte

The byte data type can store whole numbers.

Example:

byte myNum = 100;

System.out.println(myNum);

2. Short

The short data type can store whole numbers.

Example:

short myNum = 5000;

System.out.println(myNum);

3. Int

The int data type can store whole numbers. 

Example: 

int a = 10;

4. Long

The long data type can store whole numbers. This is used when int is not large enough to store the value. Note that you should end the value with an "L":

Example:

long myNum = 15000000000L;

System.out.println(myNum);

5. Float

You should use a floating point type whenever you need a number with a decimal, such as 9.99 or 3.14515.

The float data types can store fractional numbers. Note that you should end the value with an "f" for floats.

Example:

float myNum = 5.75f;

System.out.println(myNum);

6. Double

The double data type in Java is a 64-bit floating-point type used to store decimal values. It provides greater precision than float and is commonly used for scientific calculations and when higher accuracy is needed.

Example:

double myNum = 19.99d;

System.out.println(myNum);

6. Boolean

Java has a boolean data type, which can only take the values true or false:

Example:

boolean isJavaFun = true;

boolean isFishTasty = false;

System.out.println(isJavaFun);     // Outputs true

System.out.println(isFishTasty);   // Outputs false

 

Characters

The char data type is used to store a single character. The character must be surrounded by single quotes, like 'A' or 'c':

Example:

char myGrade = 'B';

System.out.println(myGrade);

Non-Primitive Data Types

Non-primitive data types are called reference types because they refer to objects rather than storing the actual value directly. They are created using constructors or by defining a class. Unlike primitive types, non-primitive types can store complex structures and data.

1. String 

A sequence of characters. 

Example:

String name = "John";


2. Array 
A collection of elements of the same type.  

Example:

int[] numbers = {1, 2, 3, 4};

3. Class 
A blueprint for creating objects with methods and properties. 

Example:

class Car {

 String model; 

}

4. Interface 

A reference type that defines abstract methods for other classes to implement. 

Example:

interface Animal {
    void makeSound();
}