Selenium Automation Testing

http://seleniumwebdriver.org/difference-between-up-casting-and-down-casting

Difference between up-casting and down-casting | Selenium Difference between up-casting and down-casting | Selenium Webdriver, RC and IDE Down-casting and up-casting was as follows: Upcasting: happens automatically, no need to do anything explicitly. Downcasting : is not directly possible in Java, explicitly we have to do. Dog d = new Dog(); Animal a = (Animal) d; //Explicitly you have done upcasting.

http://seleniumwebdriver.org/comparator-interface-in-java-with-best-examples
How we can use comparator interface ?

Comparator Interface in Java with Best Examples | Selenium Comparator Interface in Java with Best Examples | Selenium Webdriver, RC and IDE Comparator interface is used to order the objects of user-defined classes. A comparator object is capable of comparing two objects of two different classes.