[問題] 關於物件的"="是什麼概念?
public class QQ {
public static void main(String[] args){
child c1 =new child();
parent p1 =new parent();
System.out.println(p1.toString()+" "+c1.toString());
System.out.println("p1.i: "+p1.i);
p1.show();
System.out.println("c1.i: "+c1.i);
c1.show();
System.out.println("");
p1=c1;
System.out.println(p1.toString()+" "+c1.toString());
System.out.println("p1.i: "+p1.i);
p1.show();
System.out.println("c1.i: "+c1.i);
c1.show();
System.out.println("");
}
}
class parent{
int i;
parent(){}
void show(){
System.out.println("show p1.i: "+i);
}
}
class child extends parent{
int i=1;
child(){}
void show(){
System.out.println("show c1.i: "+i);
}
}
result:
parent@14a55f2 child@15093f1
p1.i: 0
show p1.i: 0
c1.i: 1
show c1.i: 1
child@15093f1 child@15093f1
p1.i: 0 <<~~!?
show c1.i: 1
c1.i: 1
show c1.i: 1
在執行p1=c1後
透過hashCode可以看到p1和c1已經變成同樣內容
為何要顯示p.i時還是指向parent的class?
還是說p1=c1只有methodc會被蓋掉,本身成員變數不會?
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