Variable and Datatype in Java

Variable and Datatype in Java

In this page, we will learn about the variable and java data types. Variable is a name of memory location. There are three types of variables: local, instance and static. There are two types of datatypes in java, primitive and non-primitive.

Variable

Variable is name of reserved area allocated in memory.

1. int data=50;//Here data is variable  

Types of Variable

There are three types of variables in java local variable instance variable static variable Local Variable A variable that is declared inside the method is called local variable. Instance Variable A variable that is declared inside the class but outside the method is called instance variable . It is not declared as static. Static variable A variable that is declared as static is called static variable. It cannot be local. We will have detailed learning of these variables in next chapters. Example to understand the types of variables 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 In java, there are two types of data types primitive data types non-primitive data types 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 Why char uses 2 byte in java and what is \u0000 ? because java uses unicode system rather than ASCII code system. \u0000 is the lowest range of unicode system.To get detail about Unicode see below.