TA貢獻1017條經(jīng)驗 獲得超1032個贊
這里是父類引用指向一個子類對象（上轉(zhuǎn)型對象），這是一種多態(tài)的體現(xiàn)，例如：
public?class?Animal{
????public?void?say(){
????System.out.println("動物會叫");
????}
}
class?Dog?extends?Animal{
????public?void?say(){
????????System.out.println("汪汪汪~~");
????}
}
class?Snake?extends?Animal{
????public?void?say(){
????????System.out.println("嘶嘶嘶~~");
????}
}
class?Test{
????public?void?test(Animal?animal){
????????????animal.say();
????????}
????public?static?void?main(){
????????new?Test().test(new?Animal());//輸出動物會叫
????????//new?Test().test(new?Dog());//多態(tài)，輸出汪汪汪
????????//new?Test().test(new?Snake());//多態(tài)，輸出嘶嘶嘶
????}
}還有就是接口回調(diào)：
public?interface?Animal{
?????void?say();
}
class?Dog?implements?Animal{
????public?void?say(){
????????System.out.println("汪汪汪~~");
????}
}
class?Snake?implements?Animal{
????public?void?say(){
????????System.out.println("嘶嘶嘶~~");
????}
}
class?Test{
????public?void?test(Animal?animal){
????????????animal.say();
????????}
????public?static?void?main(){
????????new?Test().test(new?Dog());//多態(tài)，輸出汪汪汪
????????new?Test().test(new?Snake());//多態(tài)，輸出嘶嘶嘶
????}
}
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