Types and variables:
There are three types of variables in Java :
1.Local- A variable declared inside the method is called local variable.
2.Instance- A variable declared inside inside a class and outside of methods is called instance variable
3.Static- A variable that is declared as static is called static variable. It cannot be local.
Example:
public class TypesAndVariables {
static int staticVariable=10;// Static variable
int globalvariable=25;//Global Variable/instance variable
public static void main(String[] args) {
// TODO Auto-generated method stub
int localvariable=15;// Local variable inside a method.
System.out.println(staticVariable+” “);
}
}
All Data in Java can be divided into two types:
1.Primitive
2.Non primitive
Primitive data types- There are eight primitive data type in Java:
Data Type
| 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 |
Non primitive data types are: Array, Strings etc(will be discussed later in detail).
Examples:
Adding two variables:
public class VariablesExamles {
public static void main(String[] args) {
int a=5;
int b=6;
System.out.println(“sum of a &b =”+(a+b));
}
}
output: sum of a &b =11.
We can convert one datatype into another considering Typecasting Rules.