cau give clear explanation

[anilkumar choudary]

1)is overloading is related to one class only or it can be extended in the derived class,also
2) why we need the hash code where we use it in realtime

[Ken Blair]

1. Both. One class may have two or more methods with the same name but different signatures. When this happens it is said to be overloaded. Likewise a class may have a method with the same name and a different signature than one inherited from another class, this is still overloading.

2. See HashMap for one example.