Variable Declaration:

Varaibles are the place holder which are tightly coupled with datatypes in java.
Ex:
String name = "Kalam";
int age = 71;

Rules for variables:
1. Variables must be starting with datatypes
2. Variable name should not start with number but can end with number
Ex: 
String person1 = "Modi"; ==> Correct
String 1Person = "Modi" ==> Incorrect
3. No special characters are allowed in the variable name except underscore (_)
Ex: String person_Name = "Raju";
int person_age = 25;
4. The reserved keywors should not be used as variable.
Ex: break, continue, class, interface, object etc


Different ways of declaring the variables:
case1: Declare the variable first and later add the value
String name;
name = "Kalam";

int age;
age = 71;


Case2: Declaration and allocatoin at the same time
EX:
String name = "Modi";
int age = 70;

Case3: Declare all the similar types together and later add the value
String name, city, gender;
name = "Bhagath";
city = "Punjab";
gender = "Male";

int age, pincode, accNum;
age = 21;
pincode = 560104
accNum = 12345

