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?()
第1题:
有如下程序:
include<iostream>
using namespace std;
class Pet{
char name[10];
public:
Pet(char*name){strcpy(this->name,name);}
const char*getName()const {return name;}
virtual void call()const=0;
};
class Dog:public Pet{
public:
Dog(char*name):Pet(name){}
void call()const{cout<<"汪汪叫":}
};
class Cat:public Pet{
public:
Cat(char*name):Pet(name){}
void call()const{cout<<"喵喵叫";}
};
int main(){
Pet*pet1=new Dog("哈克"),*pet2=new Cat("吉米");
cout<<pet1->getName();pet1->call();cout<<end1;
cout<<pet2->getName();pet2->call();cout<<end1;
return 0;
}
程序的输出结果是______。
第2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{pubilc abstract void speak( );}
D.public abstract class Animal{pubile abstract void speak( ){};}
第3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(){}}
第4题:
10. interface Jumper { public void jump(); } ...... 20. class Animal {} ...... 30. class Dog extends Animal { 31. Tail tail; 32. } ...... 40. class Beagle extends Dog implements Jumper { 41. public void jump() { } 42. } ....... 50. class Cat implements Jumper { 51. public void jump() { } 52. } Which three are true?()
第5题:
class One { public One() { System.out.print(1); } } class Two extends One { public Two() { System.out.print(2); } } class Three extends Two { public Three() { System.out.print(3); } } public class Numbers{ public static void main( String[] argv) { new Three(); } } What is the result when this code is executed?()
第6题:
有如下程序:
nclude<iostream>
using namespace std;
class Animal{
public:
virtual char*getType()const{return“Animal”;}
virtual char*getVoice()const{return“Voice”;}
};
class Dog:public Animal{
public:
char*getType()const{rgturn“Dog”;}
char*getVoice()const{retum“Woof”;}
};
void type(Animal&A){cout<<a.getType();}
void speak(AnimalA){cout<<a.getVoice();}
int main(){
Dog d.type(D);tout<<“speak”;speak(D);cout<<endl;
return 0;
}
运行时的输出结果是【 】
第7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{ pubilc abstract void speak;}
D.public abstract class Animal{ pubile abstract void speak{};}
第8题:
如下程序的输出结果是______。
include<iostream>
using namespace std;
class Pet{
char name[10];
public:
Pet(char*nanle){strcpy(this->name,name);}
const char*getName( )const{return name;}
virtual void call( )eonst=0;
};
class Dog:public Pet{
public:
Dog(char*name):Pet(name){ }
void call( )eonst{cout<<"汪汪叫";}
};
class Cat:public Pet{
public:
Cat(char*name):Pet(name){ }
void call( )const{eout<<"喵喵叫";}
};
int main( ){
Pet*petl=new Dog("哈克"),*pet2=new Cat("吉米");
eout<<petl->getName( );petl->call( );eout<<endl;
cout<<pet2->getName( );pet2->call( );eout<<endl;
return 0;
}
第9题:
public class Pet{ private String name; public Pet(){ System.out.print(1); } public Pet(String name){ System.out.print(2); } } public class Dog extends Pet{ public Dog(String name){ System.out.print(3); } } 执行new Dog(“棕熊”);后程序输出是哪项?()
第10题:
public class Pet{ private String name; public Pet(String name){ this.name = name; } public void speak(){ System.out.print(name); } } public class Dog extends Pet{ public Dog(String name){ super(name); } public void speak(){ super.speak(); System.out.print(“ Dog ”); } } 执行代码 Pet pet = new Dog(“京巴”); pet.speak(); 后输出的内容是哪项?()