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Vector <×ÓÀà> vec = £¨Vector <×ÓÀà>£©Vector <¸¸Àà>  ÕâÑùת²»ÁË

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Vector <×ÓÀà>
Vector <¸¸Àà>
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¶ÔÓÚ£ºVector <×ÓÀà> vec = £¨Vector <×ÓÀà>£©Vector <¸¸Àà>
¿ÉÒÔÊÓ×÷£ºVector vec = £¨Vector£©Vector£¬
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Java code:

class p{
String p="p";
}
class c extends p{
String c="c";
}
public class Main {

public static void main(String[] args) {
Vector<c> cc=new Vector();
cc.add(new c());
Vector<p> pp=(Vector)cc;
System.out.println(&qu


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