Java basics-method overloading and method Rewriting

1. Method overload)

Method overloading means that multiple methods have the same name, but different method parameters. Different method parameters have two meanings: one is that the parameter types are different, and the other is that the number of parameters is different. A typical example is that one of our classes can have many constructor methods. By default, the constructor without parameters is used. The Return Value of the method has no effect on the overload. In the following example, compilation fails:

Public int sayhello () {return 1;} public Boolean sayhello () {return false ;}

2. Override)

Override of a method is also called overwrite. The return type of a subclass and its parent class is the same, the method name is the same, and the parameters are the same. In this way, the Child class and the parent class constitute an overwrite relationship.

Public Class Parent {/*** sayhello () method of the parent class */Public void sayhello () {system. out. println ("hello") ;}} public class Child extends parent {/** subclass overrides the sayhello () method of the parent class */@ overridepublic void sayhello () {system. out. println ("Hello World ");}}

In fact, there is a simple distinction between method overloading and method Rewriting:

1. Method overloading occurs in two or more methods of the same class;

2. Method rewriting occurs between the parent class and the subclass.