| 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.
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;
- static int m=100;
- void method(){
- int n=90;
- }
- }
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.
