متغیر یا Variable

int data=50;

class A {  

    int data = 50; // instance variable  

    static int m = 100; // static variable  

    void method () {  

        int n = 90; // local variable  

    }  

} //end of class

Data Types in Java

boolean

char

byte

short

int

long

float

double

Data-Type  Default-Value  Default-size

boolean    false          1 bit

char       '\u0000'       2 byte

byte       0              1 byte

short      0              2 byte

int        0              4 byte

long       0L             8 byte

float      0.0f           4 byte

double     0.0d           8 byte

class Simple {  

    public static void main (String[] args) {  

        int a = 10;  

        int b = 10;  

        int c =  a + b;  

        System.out.println(c);  

    }

}

--------------------------------------------

Output: 
20

class Simple {  

    public static void main (String[] args) {  

        int a = 10;  

        float f = a;  

        System.out.println(a);  

        System.out.println(f);  

    }

}

--------------------------------------------

Output:

10

10.0