Java中的变量

public class DemoJava {
   public static void main(String []args) {

      int a;
      int b;

      a = 10;
      b = 20;

      System.out.println("Value of a = " + a);
      System.out.println("Value of b = " + b);

      System.out.println("Value of a = " + a + " and value of b = " + b);     
   }
}