2021年石化盈科笔试题.doc

2021年石化盈科笔试题
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public class Encapsulation {
class ClassValue{
public int i=15;

}
public static void main(String[] args) {
// TODO Auto-generated method stub
Encapsulation t=new Encapsulation();
();
}


public void first(){
ClassValue cv=new ClassValue();
second(cv);
(":"+);

}
public void second(ClassValue v){
ClassValue cv=new ClassValue();
=25;
v=cv;
(":"+);


}
}

class A {
public void show() {
("class a show ");
}
}
class B extends A {
public void show() {
("class a show ");
}
}
public class Inherit {
/**
* ***@param args
*/
public static void main(String[] args) {
A a = new B();
if (a instanceof A) {
("A ");
}
if (a instanceof B) {
("B ");
}
}
}

public class Polymorphic {
/**
* ***@param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Parent pare = new Sub();
();
}
}
class Parent {
public void show() {
("class Parent show ");
}
}
class Sub extends Parent {
public void show() {
("class