设有如下代码:
interface IFace{}
class CFace implements IFace{}
class Base{}
public class ObRef extends Base{
public static void main(String argv[]){
ObRef bj = new ObRef();
Base b = new Base();
Object obj1 = new Object();
IFace obj2 = new CFace();
//Here
}
}
则在 //Here处插入哪个代码将不出现编译和运行错误。
A.obj1=obj2;
B.b=obj;
C.obj=b;
D.obj1=b;
第1题:
如下程序的输出是 #include<iostream> using namespace std; class Base{ public: Base( ){cout<<"BB";f( );} void f( ){cout<<"Bf";} }; class Derived:public Base{ public: Derived( ){eout<<"DD";} void f( ){cout<<"Df";} }; int main( ){Derived d;return 0;}
A.BBBff)D
B.BBDfDDDf
C.DD
D.DDBBBf
第2题:
有如下程序: #include <iostream> using namespace std; class BASE{ public: ~BASE(){cout<<"BASE";} }; class DERIVED:public BASE{ public: ~DERIVED(){cout<<"DERIVED";} }; int main(){DERIVED x;return 0;} 执行后的输出结果是
A.BASE
B.DERIVED
C.BASEDERIVED
D.DERIVEDBASE
第3题:
有如下程序: #include<iostream>#include<iosream> using namespace std; class BASE{ char c; public; BASE(char n):c(n){} virtual ~ BASE(){cout<<c;} }; class DERIVED; public BASE{ char c; public: DERIVED (char n): BASE (n+1)
A.XY
B.YX
C.X
D.Y
第4题:
此题为判断题(对,错)。
第5题:
interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?()
第6题:
package geometry; public class Hypotenuse { public InnerTriangle it = new InnerTriangle(); class InnerTriangle { public int base; public int height; } } Which is true about the class of an object that can reference the variable base? ()
第7题:
Which the two demonstrate an “is a” relationship?()
第8题:
public class Session implements Runnable, Clonable{ public void run ();public Object clone () ; }
public class Session extends Runnable, Cloneable { public void run() {/*dosomething*/} public Object clone() {/*make a copy*/} }
public abstract class Session implements Runnable, Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
public class Session implements Runnable, implements Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
第9题:
public class Employee extends Info implements Data { public void load() { /*do something*/ } }
public class Employee implements Info extends Data { public void load() { /*do something*/ } }
public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }
public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }
public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }
public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }
第10题:
It can be any class.
No class has access to base.
The class must belong to the geometry package.
The class must be a subclass of the class Hypotenuse.
第11题:
0
1
2
3
第12题:
1
2
3
4
第13题:
有以下程序:
include<iostream>
using namespace std;
class Base
{
public:
Base()
{
K=0;
}
int x;
};
class Derivedl:virtual public Base
{
public:
Derivedl()
{
x=10;
}
};
class Derived2:virtua1 public Base
第14题:
有如下程序: #include<iostream> using namespace std; class BASE{ public: ~BASE( ){cout<<"BASE";} }; class DERIVED:public BASE{ public: ~DERIVED( ){cout<<"DERIVED";} }; int main( ){DERIVED x;return 0;} 程序的输出结果是
A.BASE
B.DERIVED
C.BASEDERIVED
D.DERIVEDBASE
第15题:
设有如下代码:
class Base{}
public class MyCast extends Base{
static boolean b1=false;
static int i = -1;
static double d = 10.1;
public static void main(String argv[]){
MyCast m = new MyCast();
Base b = new Base();
//Here
}
}
则在 //Here处插入哪个代码将不出现编译和运行错误。
A.b=m;
B.m=b;
C.d =i;
D.b1 =i;
第16题:
Which three demonstrate an “is a” relationship?()
第17题:
下列代码正确的是哪项?()
第18题:
现有: interface Data {public void load();} abstract class Info {public abstract void load();} 下列类定义中正确使用Data和Info的是哪项?()
第19题:
Which two demonstrate an “is a” relationship?()
第20题:
public class Employee implements Info extends Data { public void load(){/*dosomething*/} }
public class Employee extends Inf.implements Data{ public void load() {/*do something*/} }
public class Empl.yee implements Inf extends Data{ public void Data.1oad(){* do something*/} public void load(){/*do something*/} }
public class Employee extends Inf implements Data { public void Data.1oad() {/*do something*/) public void info.1oad(){/*do something*/} }
第21题:
public class X { } public class Y extends X { }
public interface Shape { } public interface Rectangle extends Shape{ }
public interface Color { } public class Shape { private Color color; }
public interface Species { } public class Animal { private Species species; }
public class Person { } public class Employee { public Employee(Person person) { }
interface Component { } class Container implements Component { private Component[] children; }
第22题:
public interface Person { } public class Employee extends Person { }
public interface Shape { } public class Employee extends Shape { }
public interface Color { } public class Employee extends Color { }
public class Species { } public class Animal (private Species species;)
interface Component { } Class Container implements Component ( Private Component[ ] children; )
第23题:
public interface Person {} Public class Employee extends Person {}
public interface Shape {} public interface Rectangle extends Shape {}
public interface Color {} public class Shape { private Color color; }
public class Species {} public class Animal { private Species species; }
interface Component {} Class Container implements Component {private Component [] children;