DataTypes and Variables in java

 

Data Types describe the size and type of variable while Variables are container for storing value.

In java there is eight primitives Data Types :

DataType	Size	Description
byte	       1byte	Stores whole numbers from -128 to 127
short	       2bytes	Stores whole numbers from -32,768 to 32,767
int	       4bytes	Stores whole numbers from -2,147,483,648 to 2,147,483,647
long	       8bytes	Stores whole numbers from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
float	       4bytes	Stores fractional numbers. Sufficient for storing 6 to 7 decimal digits
double	       8bytes	Stores fractional numbers. Sufficient for storing 15 decimal digits
boolean	       1bit	Stores true or false values
char	       2bytes	Stores a single character/letter or ASCII values

Creating variables 

Byte 

byte Number = 100;
System.out.println(Number);

int

int Number = 100;
System.out.println(Number);

short

short Number = 100;
System.out.println(Number);

long

long Number = 100;
System.out.println(Number);

double

double Number = 100;
System.out.println(Number);

float

float Number = 10.0f;
System.out.println(Number);

boolean

boolean Number = true;
System.out.println(Number);

char

char Number = 'A';
System.out.println(Number);

Example

public class Main {
  public static void main(String[] args) {
  
    int myNum = 5;               // Integer (whole number)
    float myFloatNum = 5.99f;    // Floating point number
    char myLetter = 'D';         // Character
    boolean myBool = true;       // Boolean
    String myText = "Hello";     // String
    
    
    System.out.println(myNum);
    System.out.println(myFloatNum);
    System.out.println(myLetter);  
    System.out.println(myBool);  
    System.out.println(myText);
    
  }
}