Learn more about overloading and overriding methods in Java

First, we'll talk about the overloads of the method:

　　The overload of Java is that you can create multiple methods in a class that have the same name but have different parameters.

Determine if overloading has only two conditions:

1) The same method name

2) The different parameters are as follows:

A, the method parameter type is different

B, the method parameter number is different

C, method parameters are arranged in different order

The code is as follows:

 PackageCom.tocean.test;//Package Name Public classTest1 { Public voidNameint i) {System.out.println ("Overloading"); }            //method types are different     Public voidname (String name) {System.out.println ("Overloading"); }           //method parameter number is different     Public voidNameint i,string name,double c) {System.out.println ("Overloading"); }    //parameters are arranged in different order     Public voidNameDouble C,int I, String name) {System.out.println ("Overloading"); }}  

Independent of method return value and permission modifier

The code is as follows:

1  PackageCom.tocean.test;//Package Name2  Public classTest1 {3     //independent of method return value4      Public intNameinti,string name) {        5         returni; 6     }       7     //independent of permission modifiers8     Private voidNameDoublec) {9System.out.println ("Overloading"); Ten     } One}

In addition is the rewriting of the method:

Java's overriding premise is inheritance, inheriting subclasses do not want to inherit the parent class's methods intact, but want to make some modifications, which requires a method of rewriting.

　　There are five criteria for determining whether to rewrite:

A, the same method name

B: The same method parameters

C: Permission modifier cannot be narrower than parent class

D: Throwing exceptions cannot be more than parent class

E: The return value is consistent with the return value of the parent class or its subclasses

The code is as follows:

 Package com.tocean.test;  Public class Father {    publicvoid  Getsay (String str) {        System.out.println ("The parent class is saying:" + str);}    } class extends father{    // access modifier cannot be narrower than parent class, not method override    privatevoid Getsay (String str) {        System.out.println ("subclass in said:" +str);}    }

 Packagecom.tocean.test;Importjava.io.IOException; Public classFather { Public voidGetsay (String str)throws Exception{System.out.println ("The parent class is saying," +str); }}classSonextendsfather{//the method thrown is more than the parent class, not a method override (note the number of exceptions, not the range of exceptions)    Private voidGetsay (String str)throws ioexception,runtimeexception{System.out.println ("The subclass is saying:" +str); }}

 Packagecom.tocean.test; Public classFather { Public string getsay (String str) {System.out.println ("The parent class is saying," +str); returnstr; }}classSonextendsfather{//The return value of the method is the same as the parent class, which is the override of the method     Public string getsay (String str) {System.out.println ("The subclass is saying:" +str); returnstr; }}

 Packagecom.tocean.test; Public classFather { Public Object getsay (String str) {System.out.println ("The parent class is saying," +str); returnstr; }}classSonextendsfather{//The return value of the method is not the same as the parent class, but its subclass is the method's override     Public string getsay (String str) {System.out.println ("The subclass is saying:" +str); returnstr; }}

Learn more about overloading and overriding methods in Java