2021-04-25

课堂代码
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package edu.xcdq;

public class Demo01 {
public static void main(String[]args){
UncleOne dajiu = new UncleOne();
dajiu.fahongbao();

    //多态
    Uncle dajiu1 = new UncleOne();
    dajiu1.faHongbao();
    // 子类独有的方法在发生向上转型的时候会无法在父类当中去使用
    //dajiu1.songYan();   //会报错
    UncleOne temp = (UncleOne)dajiu1;
    temp.songYan();

    Uncle erjiu = new UncleTow();
    erjiu.faHongbao();

    /*//向下转型
    UncleOne uncle1 = (UncleOne) new Uncle();
    UncleTow temp = (UncleTow) uncleTow;
    uncle1.fahongbao();*/

}

}

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package edu.xcdq;

public class Uncle {
private String name;
private int age;

public Uncle(){
}

public Uncle(String name,int age){
    this.name = name;
    this.age = age;
}
public void setName(String name){
    this.name = name;
}
public int getAge(){
    return age;
}
public void setAge(int age){
    this.age = age;
}
@Override
public String toString(){
    return "Uncle{"+
            "name'"+name + '\''+
            ",age = " + age +
            '}';
}
public void faHongbao(){
    System.out.println("舅舅发红包");
}

}

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package edu.xcdq;

public class UncleOne extends Uncle {
public void fahongbao(){
System.out.println("大舅发红包");
}
public void songYan(){
System.out.println("大舅喜欢送烟");
}

}

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package edu.xcdq;

public class UncleTow extends Uncle {

public void fahongbao(){
    System.out.println("二舅发红包");
}

}

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