The difference between overloading and rewriting in Java: 1. Overloading occurs in this class, and rewriting occurs between the parent class and the subclass; 2. The overloaded method name must be the same, and rewriting The method names are the same and the return value types must be the same; 3. The overloaded parameter lists are different, and the overridden parameter lists must be the same.
Overloading
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Overloading Occurs in this class, the method name is the same, the parameter list is different, it has nothing to do with the return value, it is only related to the method name, parameter list, and parameter type.
Overload (Overload): First, it is located in a A class or its subclass has the same method name, but the method parameters are different, and the return value type can be the same or different.
(1): The method names must be the same
(2): The parameter lists of the methods must be different.
(3): The access modifier and return value type can be the same or different.
In fact, to put it simply: overloading means writing different methods for different situations. For example, in the same class, write different constructors to initialize different parameters.
Overriding
Overriding occurs between parent classes and subclasses. For example, all classes inherit from the Object class. The Object class itself has equals, hashcode, and toString. Methods, etc. Defining the same name and the same parameter list in any subclass constitutes method overriding.
Override: generally represents the relationship between the subclass and the parent class. Its main purpose is to express the relationship between the subclass and the parent class. The characteristics are: the method name is the same, the parameters are the same, but the specific implementation is different.
Characteristics of rewriting:
(1): The method name must be the same and the return value type must be the same
(2): The parameter list must be the same
(3): The access permission cannot be lower than the access permission of the overridden method in the parent class. For example: If a method of the parent class is declared as public, then the method cannot be declared as protected when overriding it in the subclass.
(4): If the subclass and the parent class are in the same package, then the subclass can override all methods of the parent class, except for methods declared as private and final.
(5): The construction method cannot be overridden.
To put it simply: the specific implementation class is not satisfied with the implementation of the method of the parent class, and needs to write one that satisfies itself. required method.
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