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1. interface Animal {   2. void eat();   3. }   4.   5. // insert code here   6.   7. public class HouseCat implements Feline {   8. public void eat() { }   9. }   和以下三个接口声明:   interface Feline extends Animal { }   interface Feline extends Animal { void eat(); }   interface Feline extends Animal { void eat() { } }   分别插入到第 5 行,有多少行可以编译?()

  • A、0
  • B、1
  • C、2
  • D、3

参考答案

更多 “ 1. interface Animal {   2. void eat();   3. }   4.   5. // insert code here   6.   7. public class HouseCat implements Feline {   8. public void eat() { }   9. }   和以下三个接口声明:   interface Feline extends Animal { }   interface Feline extends Animal { void eat(); }   interface Feline extends Animal { void eat() { } }   分别插入到第 5 行,有多少行可以编译?()A、0B、1C、2D、3” 相关考题
考题 1. public class SimpleCalc {  2. public int value;  3. public void calculate() { value += 7; }  4. } And:  1. public class MultiCalc extends SimpleCalc {  2. public void calculate() { value -= 3; }  3. public void calculate(int multiplier) {  4. calculate();  5. super.calculate();  6. value *=multiplier;  7. }  8. public static void main(String[] args) {  9. MultiCalc calculator = new MultiCalc();  10. calculator.calculate(2);  11. System.out.println(”Value is: “+ calculator.value);  12. }  13. }  What is the result?() A、 Value is: 8B、 Compilation fails.C、 Value is: 12D、 Value is: -12E、 The code runs with no output.F、 An exception is thrown at runtime.

考题 1. public class GoTest {  2. public static void main(String[] args) {  3. Sente a = new Sente(); a.go();  4. Goban b = new Goban(); b.go();  5. Stone c = new Stone(); c.go();  6. }  7. } 8.  9. class Sente implements Go {  10. public void go() { System.out.println(”go in Sente.”); }  11. }  12.  13. class Goban extends Sente {  14. public void go() { System.out.println(”go in Goban”); }  15. }  16.  17. class Stone extends Goban implements Go { }  18.  19. interface Go { public void go(); }  What is the result?() A、 go in Goban  go in Sente go in SenteB、 go in Sente  go in Sente go in GobanC、 go in Sente  go in Goban go in GobanD、 go in Goban go in Goban go in SenteE、 Compilation fails because of an error in line 17.

考题 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.

考题 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?()A、 Cat is-a AnimalB、 Cat is-a JumperC、 Dog is-a AnimalD、 Dog is-a JumperE、 Cat has-a AnimalF、 Beagle has-a TailG、 Beagle has-a Jumper

考题 Which three demonstrate an “is a” relationship?() A、 public class X { }  public class Y extends X { }B、 public interface Shape { }  public interface Rectangle extends Shape{ }C、 public interface Color { }  public class Shape { private Color color; }D、 public interface Species { }  public class Animal { private Species species; }E、 public class Person { } public class Employee {  public Employee(Person person) { }F、 interface Component { }  class Container implements Component { private Component[] children; }

考题 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*/ } }

考题 1. public class Exception Test {  2. class TestException extends Exception {}  3. public void runTest() throws TestException {}  4. public void test() /* Point X */ {  5. runTest();  6. }  7. }  At Point X on line 4, which code is necessary to make the code compile?()  A、 No code is necessary.B、 throws ExceptionC、 catch ( Exception e )D、 throws RuntimeExceptionE、 catch ( TestException e)

考题 现自:  1.  interface Color {  }      2. interface Weight  {  }      3.  //insert code here    和以下足六个声明:  class Boat extends Color, extends Weight  {  }     class Boat extends Color and Weight  {  }      class Boat extends Color, Weight  {  }  class Boat implements Color,  implements Weight  {  }     class Boat implements Color and Weight  {  }      class Boat implements Color, Weight  {  }    分别插入到第3行,有多少行可以编译? () A、  0B、  1C、  2D、  3

考题 interface Animal {  void soundOff();  }  class Elephant implements Animal {  public void soundOff() {  System.out.println(“Trumpet”);  }  }  class Lion implements Animal {  public void soundOff() { System.out.println(“Roar”);  }  }  class Alpha1 {  static Animal get( String choice ) {  if ( choice.equalsIgnoreCase( “meat eater” )) {  return new Lion();  } else {  return new Elephant();  }  }  }  Which compiles?()  A、 new Animal().soundOff();B、 Elephant e = new Alpha1();C、 Lion 1 = Alpha.get(“meat eater”);D、 new Alpha1().get(“veggie”).soundOff();

考题 现有:  interface Animal {       void eat () ;       }       //insert code here       public class HouseCat extends Feline {       public void eat() { }       }  和五个申明  abstract class Feline implements Animal { }  abstract  class  Feline  implements  Animal  {  void eat () ;  }  abstract class Feline implements Animal { public void eat();}  abstract class Feline implements Animal { public void eat() {}  }  abstract class Feline implements Animal { abstract public void eat();} 结果为:()      A、1B、2C、3D、4

考题 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*/}     }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*/}    }

考题 Which the two demonstrate an “is a” relationship?()A、 public interface Person {}  Public class Employee extends Person {}B、 public interface Shape {}  public interface Rectangle extends Shape {}C、 public interface Color {}  public class Shape { private Color color; }D、 public class Species {}  public class Animal { private Species species; }E、 interface Component {} Class Container implements Component {private Component [] children;

考题 interface A { public int getValue() }  class B implements A {  public int getValue() { return 1; }  }  class C extends B {  // insert code here  }  Which three code fragments, inserted individually at line 15, make use of polymorphism?()A、 public void add(C c) { c.getValue(); }B、 public void add(B b) { b.getValue(); }C、 public void add(A a) { a.getValue(); }D、 public void add(A a, B b) { a.getValue(); }E、 public void add(C c1, C c2) { c1.getValue(); }

考题 Which two demonstrate an “is a” relationship?()   A、 public interface Person { }  public class Employee extends Person { }B、 public interface Shape { }  public class Employee extends Shape { }C、 public interface Color { }  public class Employee extends Color { }D、 public class Species { }  public class Animal (private Species species;)E、 interface Component { }  Class Container implements Component ( Private Component[ ]children;  )

考题 1. class Animal { Animal getOne() { return new Animal(); } }  2. class Dog extends Animal {  3. // insert code here   4. }  5.  6. class AnimalTest {  7. public static void main(String [] args) {  8. Animal [] animal = { new Animal(), new Dog() } ;  9. for( Animal a : animal) {  10. Animal x = a.getOne();  11. }  12. }  13. }  和代码:  3a. Dog getOne() {  return new Dog();  }  3b. Animal getOne() {  return new Dog();  }  第 3 行中插入的哪项将编译且运行无异常?() A、3a行B、3b行C、3a行或3b行D、既非3a,也非3b

考题 现有:  1. interface Animal {  2. void eat();  3. }  4.  5. // insert code here  6.  7. public class HouseCat extends Feline {  8. public void eat() { }  9. }   和五个声明:  abstract class Feline implements Animal { }  abstract class Feline implements Animal { void eat(); }  abstract class Feline implements Animal { public void eat(); }  abstract class Feline implements Animal { public void eat() { } }  abstract class Feline implements Animal { abstract public void eat(); }  分别插入到第5行,有几个可以通过编译?() A、0B、1C、2D、3

考题 现有:   1. interface Animal {    2.   void eat();   3.  }    4.   5. // insert code here    6.   7. public class HouseCat implements Feline {    8.   public void eat() { }   9. }   和以下三个接口声明:   interface Feline extends Animal { }    interface Feline extends Animal { void eat(); }     interface Feline extends Animal { void eat() { } }    分别插入到第 5 行,有多少行可以编译?()  A、 0B、 1C、 2D、 3

考题 public abstract class Shape {  private int x;  private int y;  public abstract void draw();  public void setAnchor(int x, int y) {  this.x = x;  this.y = y;  }  }  Which two classes use the Shape class correctly?()A、 public class Circle implements Shape { private int radius; }B、 public abstract class Circle extends Shape { private int radius; }C、 public class Circle extends Shape { private int radius; public void draw(); }D、 public abstract class Circle implements Shape { private int radius; public void draw(); }E、 public class Circle extends Shape { private int radius;public void draw() {/* code here */} }F、 public abstract class Circle implements Shape { private int radius;public void draw() { / code here */ } }

考题 1. interface A { public void aMethod(); }  2. interface B { public void bMethod(); }  3. interface C extends A,B { public void cMethod(); }  4. class D implements B {  5. public void bMethod() { }  6. }  7. class E extends D implements C {  8. public void aMethod() { }  9. public void bMethod() { }  10. public void cMethod() { }  11. }  What is the result?() A、 Compilation fails because of an error in line 3.B、 Compilation fails because of an error in line 7.C、 Compilation fails because of an error in line 9.D、 If you define D e = new E(), then e.bMethod() invokes the version of bMethod()defined in Line 5.E、 If you define D e = (D)(new E()),then e.bMethod() invokes the version of bMethod() defined in Line 5.F、 If you define D e = (D)(new E()), then e.bMethod() invokes the version of bMethod() defined in Line 9.

考题 多选题Which two demonstrate an “is a” relationship?()Apublic interface Person { }  public class Employee extends Person { }Bpublic interface Shape { }  public class Employee extends Shape { }Cpublic interface Color { }  public class Employee extends Color { }Dpublic class Species { }  public class Animal (private Species species;)Einterface Component { }  Class Container implements Component ( Private Component[ ]children;  )

考题 单选题1. public class Exception Test {  2. class TestException extends Exception {}  3. public void runTest() throws TestException {}  4. public void test() /* Point X */ {  5. runTest();  6. }  7. }  At Point X on line 4, which code is necessary to make the code compile?()A  No code is necessary.B  throws ExceptionC  catch ( Exception e )D  throws RuntimeExceptionE  catch ( TestException e)

考题 单选题interface Animal {  void soundOff();  }  class Elephant implements Animal {  public void soundOff() {  System.out.println(“Trumpet”);  }  }  class Lion implements Animal {  public void soundOff() { System.out.println(“Roar”);  }  }  class Alpha1 {  static Animal get( String choice ) {  if ( choice.equalsIgnoreCase( “meat eater” )) {  return new Lion();  } else {  return new Elephant();  }  }  }  Which compiles?()A  new Animal().soundOff();B  Elephant e = new Alpha1();C  Lion 1 = Alpha.get(“meat eater”);D  new Alpha1().get(“veggie”).soundOff();

考题 多选题Which the two demonstrate an “is a” relationship?()Apublic interface Person {}  Public class Employee extends Person {}Bpublic interface Shape {}  public interface Rectangle extends Shape {}Cpublic interface Color {}  public class Shape { private Color color; }Dpublic class Species {}  public class Animal { private Species species; }Einterface Component {} Class Container implements Component {private Component [] children;

考题 单选题现有:   1. interface Animal {    2.   void eat();   3.  }    4.   5. // insert code here    6.   7. public class HouseCat implements Feline {    8.   public void eat() { }   9. }   和以下三个接口声明:   interface Feline extends Animal { }    interface Feline extends Animal { void eat(); }     interface Feline extends Animal { void eat() { } }    分别插入到第 5 行,有多少行可以编译?()A  0B  1C  2D  3

考题 多选题Which three demonstrate an “is a” relationship?()Apublic class X { }  public class Y extends X { }Bpublic interface Shape { }  public interface Rectangle extends Shape{ }Cpublic interface Color { }  public class Shape { private Color color; }Dpublic interface Species { }  public class Animal { private Species species; }Epublic class Person { } public class Employee {  public Employee(Person person) { }Finterface Component { }  class Container implements Component { private Component[] children; }

考题 多选题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?()ACat is-a AnimalBCat is-a JumperCDog is-a AnimalDDog is-a JumperECat has-a AnimalFBeagle has-a TailGBeagle has-a Jumper

考题 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*/ } }

考题 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*/}     }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*/}    }