reference variable in java code example

Example 1: Variables in java

// instance variable in java example
public class InstanceVariableDemo
{
   // instance variable declared inside the class and outside the method
   int c;
   public void subtract()
   {
      int x = 100;
      int y = 50;
      c = x - y;
      System.out.println("Subtraction: " + c);
   }
   public void multiply()
   {
      int m = 10;
      int n = 5;
      c = m * n;
      System.out.println("Multiplication: " + c);
   }
   public static void main(String[] args)
   {
      InstanceVariableDemo obj = new InstanceVariableDemo();
      obj.subtract();
      obj.multiply();
   }
}

Example 2: Variables in java

// static variable in java example
public class StaticVariableExample
{
   // static variable
   static int a = 0;
   public void add()
   {
      a++;
   }
   public static void main(String[] args)
   {
      StaticVariableExample obj1 = new StaticVariableExample();
      StaticVariableExample obj2 = new StaticVariableExample();
      obj1.add();
      obj2.add();
      // both objects are sharing same copy of static variable
      System.out.println("Object 1 value is: " + a);
      System.out.println("Object 2 value is: " + a);
   }
}

Example 3: Variables in java

// local variable in java example
public class LocalVariableExample
{
   public void employeeDetails()
   {
      // local variable empAge and name
      int empAge = 22;
      String name = "Sachin";
   }
   public static void main(String[] args)
   {
      LocalVariableExample obj = new LocalVariableExample();
      // name and empAge cannot 
      // be resolved to a variable
      System.out.println("Employee name is : " + name + ", and age : " + empAge);
   }
}

Example 4: how to create a variable java

int myVariable = 42;    //This is the most commonly used variable. Only use other variables if you have a good reason to.