下面的代码使用了面向对象的什么特性?() public class A{ public void DoSomething(){} } public class B : A{ new public void DoSomething(){ base.DoSomething();} }A.继承性B.多态性C.封装性D.关联性
下面的代码使用了面向对象的什么特性?() public class A{ public void DoSomething(){} } public class B : A{ new public void DoSomething(){ base.DoSomething();} }
A.继承性
B.多态性
C.封装性
D.关联性
参考答案和解析
PHP;JAVA;C++;C#
相关考题:
下列程序片段中,能通过编译的是A.public abstract class Animal{ public void speak();}B.public abstract class Animal{ public void speak(){}}C.public class Animal{ public abstract void speak();}D.public abstract class Animal{ public abstract void speak(){}}
下列关于Test类的定义中,正确的是______。A) class Test implements Runnabte{public void run(){}public void someMethod(){}B) class Test implements Rnuuable{public void run();}C) class Test implements Rnuuable{public void someMethod();}D) class Test implements Rnuuable{public void someMethod();{}}A.B.C.D.
下列程序的运行结果是______。 include class A { public: virtual void use( ) {cou 下列程序的运行结果是______。include<iostream.h>class A{public:virtual void use( ) {cout<<"in A\n";}};class B:public A{public:virtual void use( ) {cout<<"in B\n";}};class C:public B{public:virtual void use( ){cout"in C\n";}};void main( ){A*obj;bj=new C;obj->use( );delete obj;}
下面程序的运算结果是()。includeusing namespace std;class A{public:virtual void f 下面程序的运算结果是( )。 #include<iostream> using namespace std; class A { public: virtual void fun()=0; }; class B:public A } public: void fun() {cout<<"new file"<<" ";} }; class C:public A { public: void fun() { cout<<"open file"<<" ";} }; void main() { A a, * p; B b;C c; p=c; p->fun(); p=b; }A.new file open fileB.new file new fileC.编译出错D.open file new file
请在每条横线处填写一个语句,使程序的功能完整,且输出结果为91 1。注意:请勿改动main()主方法和其他已有的语句内容,仅在横线处填入适当的语句。源程序文件代码清单如下:public class Outer{public static void main (String args[]{Outer i = new Outer();i,taskInner();}public class Inner{private int size;public void doSomething(int size){_____________//访问局部变量this. size++; //访问内部类的成员变量_____________//访问外部类的成员变量System.out.println(size+" "+this.size+" "+Outer.this.size);}}public void taskInner(){___________k.doSomething(8);}private static int size;}
下列程序片段中,能通过编译的是( )。A.public abstract class Animal{public void speak( );}B.public abstract class Animal{public void speak( ){};}C.public class Animal{pubilc abstract void speak( );}D.public abstract class Animal{pubile abstract void speak( ){};}
public class Something {public static void main(String[] args) {Other o = new Other();new Something().addOne(o);}public void addOne(final Other o) {o.i++;}}class Other {public int i;}和上面的很相似,都是关于final 的问题,这有错吗?
class Something {int i;public void doSomething() {System.out.println("i = " + i);}}有什么错呢? 看不出来啊。
public class Something {public static void main(String[] args) {Something s = new Something();System.out.println("s.doSomething() returns " + doSomething());}public String doSomething() {return "Do something ...";}}看上去很完美。
写出程序的输出结果public abstract class A{public A(){Console.WriteLine('A');}public virtual void Fun(){Console.WriteLine("A.Fun()");}}public class B: A{public B(){Console.WriteLine('B');}public new void Fun(){Console.WriteLine("B.Fun()");}public static void Main(){A a = new B();a.Fun();}}
下面的代码中有什么错误吗?_______using System;class A{public virtual void F(){Console.WriteLine("A.F");}}abstract class B:A{public abstract override void F();
下面程序的结果是 ______。includeclass A{ public:virtual voidfun()=0{};};class 下面程序的结果是 ______。 #include<iostream.h> class A{ public: virtual void fun()=0{}; }; class B:public A{ public: void fun () {cout<< "new file" ;} }; class C: public A{ public: void fun (){cout<<"open file"<< " " } }; class D: public A{ public: void fun () {cout<< "save file\n" ;} }; void main() { A a,*p; B b; C c; D d; p=c; p->fun (); p=b; p->fun (); p=d; p->fun(); }A.new file open file save fileB.new file new file new fileC.编译出错D.open file new file save file
下列程序片段中,能通过编译的是( )。 A.public abstract class Animal{ public void speak;}S 下列程序片段中,能通过编译的是( )。A.public abstract class Animal{ public void speak;}B.public abstract class Animal{ public void speak{);}C.public class Animal{ pubilc abstract void speak;}D.public abstract class Animal{ pubile abstract void speak{};}
阅读下列说明和 Java 代码,将应填入(n)处的字句写在答题纸的对应栏内。【说明】生成器( Builder)模式的意图是将一个复杂对象的构建与它的表示分离,使得同样的构建过程可以创建不同的表示。图 6-1 所示为其类图。阅读下列说明和C++代码,将应填入(n)处的字句写在答题纸的对应栏内。【说明】???? 生成器(Builder)模式的意图是将一个复杂对象的构建与它的表示分离,使得同样的构建过程可以创建不同的表示。图5-1所示为其类图。?【C++代码】#include #include using namespace std;class Product {private:?string partA, partB;public:?Product() {?? }? ?void setPartA(const string}???? void setPartB(const string}? ?//? 其余代码省略};class Builder {public:? ? ??(1)??;?virtual void buildPartB()=0;? ? ?(2)??;};class ConcreteBuilder1 : public Builder {private:?Product*?? product;public:ConcreteBuilder1() {product = new Product();???? }void buildPartA() {????? (3)???? ("ComponentA"); }?void buildPartB() {????? (4)???? ("ComponentB"); }??Product* getResult() { return product; }//? 其余代码省略};class ConcreteBuilder2 : public Builder {? ??? ? ? ?/*??? 代码省略??? */};class Director {private:? ??Builder* builder;public:??Director(Builder* pBuilder) { builder= pBuilder;}? ??void construct() {????????????????? (5)???? ;?????????????? //? 其余代码省略? ?}??//? 其余代码省略};int main() {? ? ??Director* director1 = new Director(new ConcreteBuilder1());? ?director1->construct();? ? ??delete director1;? ? ?return 0;【Java代码】import jav(6)A.util.*;class Product {? ? ? ?private String partA;? ? ? ?private String partB;? ? ? ??public Product() {}? ? ??public void setPartA(String s) { partA = s; }? ? ? ?public void setPartB(String s) { partB = s; }}interface Builder {? ?public?????? (1)???? ;? ??public void buildPartB();? ? ??public?????? (2)???? ;}class ConcreteBuilder1 implements Builder {? ? ? ?private Product product;? ? ? ?public ConcreteBuilder1() { product = new Product();?? }? ? ? ??public void buildPartA() {????????(3)??("Component A"); }public void buildPartB() {???? ????(4)?? ("Component B"); }? ? ??public Product getResult() { return product;}}class ConcreteBuilder2 implements Builder {?? ? ? ? ?//? 代码省略}class Director {? ? ? ?private Builder builder;? ? ? ?public Director(Builder builder) {this.builder = builder; }public void construct() {? ? ? ? ? ? ? ? ? (5)???? ;? ? ? ? ? ? ? //? 代码省略? ? ??}}class Test {? ? ??public static void main(String[] args) {???????????????? Director director1 = newDirector(new ConcreteBuilder1());???????????????? director1.construct();? ? ? ??}
public class SomeException { } Class a: public class a { public void doSomething() { } } Class b: public class b extends a { public void doSomething() throws SomeException { } } Which is true about the two classes?() A、 Compilation of both classes will fail.B、 Compilation of both classes will succeed.C、 Compilation of class a will fail. Compilation of class b will succeed.D、 Compilation of class a will fail. Compilation of class a will succeed.
1. public interface A { 2. public void doSomething(String thing); 3. } 1. public class AImpl implements A { 2. public void doSomething(String msg) { } 3. } 1. public class B { 2. public A doit() { 3. // more code here 4. } 5. 6. public String execute() { 7. // more code here 8. } 9. } 1. public class C extends B { 2. public AImpl doit() { 3. // more code here 4. } 5. 6. public Object execute() { 7. // more code here 8. } 9. } Which statement is true about the classes and interfaces in the exhibit?() A、 Compilation will succeed for all classes and interfaces.B、 Compilation of class C will fail because of an error in line 2.C、 Compilation of class C will fail because of an error in line 6.D、 Compilation of class AImpl will fail because of an error in line 2.
interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?() A、 public class Employee extends Info implements Data { public void load() { /*do something*/ } }B、 public class Employee implements Info extends Data { public void load() { /*do something*/ } }C、 public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }D、 public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }E、 public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }F、 public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }
Which two allow the class Thing to be instantiated using new Thing()?A、 public class Thing { }B、 public class Thing { public Thing() {} }C、 public class Thing { public Thing(void) {} }D、 public class Thing { public Thing(String s) {} }E、 public class Thing { public void Thing() {} public Thing(String s) {} }
public class X { public X aMethod() { return this;} } public class Y extends X { } Which two methods can be added to the definition of class Y?()A、 public void aMethod() {}B、 private void aMethod() {}C、 public void aMethod(String s) {}D、 private Y aMethod() { return null; }E、 public X aMethod() { return new Y(); }
下列代码正确的是哪项?() A、 public class Session implements Runnable, Clonable{ public void run ();public Object clone () ; }B、 public class Session extends Runnable, Cloneable { public void run() {/*dosomething*/} public Object clone() {/*make a copy*/} }C、 public abstract class Session implements Runnable, Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }D、 public class Session implements Runnable, implements Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
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?() A、 public class Employee implements Info extends Data { public void load(){/*dosomething*/} }B、public class Employee extends Inf.implements Data{ public void load() {/*do something*/} }C、public class Empl.yee implements Inf extends Data{ public void Data.1oad(){* do something*/} public void load(){/*do something*/} }D、public class Employee extends Inf implements Data { public void Data.1oad() {/*do something*/) public void info.1oad(){/*do something*/} }
单选题下列代码正确的是哪项?()A public class Session implements Runnable, Clonable{ public void run ();public Object clone () ; }B public class Session extends Runnable, Cloneable { public void run() {/*dosomething*/} public Object clone() {/*make a copy*/} }C public abstract class Session implements Runnable, Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }D public class Session implements Runnable, implements Clonable { public void run() {/*do something*/} public Object clone() {/*make a copy*/} }
单选题现有: 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?()A public class Employee implements Info extends Data { public void load(){/*dosomething*/} }Bpublic class Employee extends Inf.implements Data{ public void load() {/*do something*/} }Cpublic class Empl.yee implements Inf extends Data{ public void Data.1oad(){* do something*/} public void load(){/*do something*/} }Dpublic class Employee extends Inf implements Data { public void Data.1oad() {/*do something*/) public void info.1oad(){/*do something*/} }
单选题interface Data { public void load(); } abstract class Info { public abstract void load(); } Which class correctly uses the Data interface and Info class?()A public class Employee extends Info implements Data { public void load() { /*do something*/ } }B public class Employee implements Info extends Data { public void load() { /*do something*/ } }C public class Employee extends Info implements Data { public void load() { /*do something */ } public void Info.load() { /*do something*/ } }D public class Employee implements Info extends Data { public void Data.load() { /*dsomething */ } public void load() { /*do something */ } }E public class Employee implements Info extends Data { public void load() { /*do something */ } public void Info.load(){ /*do something*/ } }F public class Employee extends Info implements Data{ public void Data.load() { /*do something*/ } public void Info.load() { /*do something*/ } }
单选题public class Pet{ public void speak(){ System.out.print(“ Pet ”); } } public class Cat extends Pet{ public void speak(){ System.out.print(“ Cat ”); } } public class Dog extends Pet{ public void speak(){ System.out.print(“ Dog ”); } } 执行代码 Pet[] p = {new Cat(),new Dog(),new Pet()}; for(int i=0;i〈p.length;i++) p[i].speak(); 后输出的内容是哪项?()APet Pet PetBCat Cat CatCCat Dog PetDCat Dog Dog
单选题public class SomeException { } Class a: public class a { public void doSomething() { } } Class b: public class b extends a { public void doSomething() throws SomeException { } } Which is true about the two classes?()A Compilation of both classes will fail.B Compilation of both classes will succeed.C Compilation of class a will fail. Compilation of class b will succeed.D Compilation of class a will fail. Compilation of class a will succeed.
多选题Which two allow the class Thing to be instantiated using new Thing()?Apublic class Thing { }Bpublic class Thing { public Thing() {} }Cpublic class Thing { public Thing(void) {} }Dpublic class Thing { public Thing(String s) {} }Epublic class Thing { public void Thing() {} public Thing(String s) {} }