Java中具有多个类的Varargs问题
Java中具有多个类的Varargs问题
提问于 2018-12-19 09:01:37
所以当我创建具有多个类的变量参数时，我遇到了一个问题。正如您在下面的代码中看到的，我只是尝试以随机顺序获取多个城市和地区，并尝试打印出整个州的人口。除了问题之外，我不知道如何迭代我的CAndD数组，以便将所有的种群相加在一起。
代码：
public class Main {
public static void main(String args[]) {
State S = new State("Florida", new District("Miami-Dade", 2752000),
new City("Miami", 463347),
new City("Tampa", 385430),
new District("Broward", 1936000));
System.out.println("The Population is: " + S.getPopulation());
}
}
class CitiesAndDistricts {
}
class City extends CitiesAndDistricts{
String name;
int population;
public City(String name, int population) {
this.name = name;
this.population = population;
}
}
class District extends CitiesAndDistricts{
String name;
int population;
public District(String name, int population) {
this.name = name;
this.population = population;
}
}
class State {
String name;
int population;
CitiesAndDistricts[] CAndD;
public State(String name, CitiesAndDistricts ... entities) {
this.name = name;
CAndD = entities;
for(int i = 0; i < CAndD.length; i++) {
this.population += CAndD[i].population;
}
}
public int getPopulation() {
return population;
}
}如果有人能帮我解决这个问题，那就太好了！
回答 2
Stack Overflow用户
回答已采纳
发布于 2018-12-19 09:11:55
请看下面的代码，我已经将人口变量从城市和地区移到了父类：
public class Main {
public static void main(String args[]) {
State S = new State("Florida", new District("Miami-Dade", 2752000),
new City("Miami", 463347),
new City("Tampa", 385430),
new District("Broward", 1936000));
System.out.println("The Population is: " + S.getPopulation());
}
}
class CitiesAndDistricts {
int population;
}
class City extends CitiesAndDistricts{
String name;
public City(String name, int population) {
this.name = name;
this.population = population;
}
}
class District extends CitiesAndDistricts{
String name;
public District(String name, int population) {
this.name = name;
this.population = population;
}
}
class State {
String name;
int population;
CitiesAndDistricts[] CAndD;
public State(String name, CitiesAndDistricts ... entities) {
this.name = name;
CAndD = entities;
for(int i = 0; i < CAndD.length; i++) {
this.population += CAndD[i].population;
}
}
public int getPopulation() {
return population;
}
}Stack Overflow用户
发布于 2018-12-21 16:08:58
设计一个空的父类似乎并不好。在您的代码中，类City和District是相同的。我假设您想知道地点的类型(城市或地区)。更好的解决方案是将子类的所有属性移动到父类。类CitiesAndDistricts将是：
class CitiesAndDistricts {
String name;
int population;
public CitiesAndDistricts(String name, int population} {
this.name = name;
this.population = population;
}
}从这个父类，您可以扩展到类City和extend，如下所示：
class City extends CitiesAndDistricts{
public City(String name, int population) {
super(name, population);
}
}
class District extends CitiesAndDistricts{
public District(String name, int population) {
super(name, population);
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/53843216
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