a: Overriding and Overloading of methods are different manifestations of Java polymorphism. Overriding is a manifestation of polymorphism between parent class and subclass, and Overloading is a manifestation of polymorphism in a class. If a method defined in a subclass has the same name and parameters as its parent class, we say that the method is Overriding. When an object in a subclass uses this method, it will call the definition in the subclass. For it, the definition in the parent class seems to be "shielded". If multiple methods with the same name are defined in a class, they either have different parameter numbers or different parameter types, which is called method Overloading. The method of Overloaded is to change the type of the return value

Conclusion::::::

Overload: 1. It can be in a class or in a class with inheritance relationship; 2. Same name; 3. Different parameter lists (number, order and type) have nothing to do with the return value type of the method.

Override: 1. It cannot be stored in the same class, but in the inherited class; 2. The name is the same, the parameter list is the same, and the method returns the same. 3. The access modifier of the subclass method is greater than that of the parent class. 4. The check exception type of subclass is smaller than that of parent class.