4209233
Beschreibung
Quiz von bowtietigers, aktualisiert more than 1 year ago
|
Erstellt von bowtietigers
vor fast 9 Jahre
|
|
Frage 1
Frage
Which of the following choices might serve as an interface for the other choices listed?
Antworten
-
Piano
-
Drum
-
Guitar
-
Instrument
-
FrenchHorn
Frage 2
Frage
Which of the following code segments causes a compile-time error?
Antworten
-
Airplane boeing707 = new Airplane();
-
Flier boeing707 = new Flier();
-
Flier boeing707 = new Airplane();
-
Airplane boeing707 = new Airplane(); Flier airTraveler = boeing707;
-
Airplane boeing707 = new Airplane(); Flier airTraveler; airTraveler = (Airplane) beoing707;
Frage 3
Frage
Consider the following code segment.
1 Airplane skyRider = new Airplane();
2 Flier skyRider2 = skyRider;
3 Athlete skyRider3 = (Athlete) skyRider2;
4 Airplane skyRider4 = (Airplane) skyRider2;
5 Flier skyRider5 = skyRider4;
Which statement above will cause a run-time error and throw an exception?
Antworten
-
Statement 1
-
Statement 2
-
Statement 3
-
Statement 4
-
Statement 5
Frage 4
Frage
Airplane c = new Airplane();
Flier f = new Airplane();
Athlete a = new SkiJumper("Ann", "Smith");
SkiJumper s = new SkiJumper("John", "Doe");
Which of the following statements is not legal?
Antworten
-
c.fly();
-
f.fly();
-
a.train(3);
-
s.train(3);
-
a.fly();
Frage 5
Frage
Airplane c = new Airplane();
Flier f = new Airplane();
Athlete a = new SkiJumper("Ann", "Smith");
SkiJumper s = new SkiJumper("John", "Doe");
Which of the following statements needs a cast?
I. f = c;
II. a = s;
III. s = a;
Antworten
-
I only
-
II only
-
III only
-
I and II only
-
I and III only
Frage 6
Frage
Suppose class C implements an interface I by implementing all of the methods of I and no further methods. Then which of the following must be true?
Antworten
-
All instance variables or C are public.
-
All methods of C are abstract.
-
All methods of C are public.
-
All constants of C are public.
-
All instance variables of C are private.
Frage 7
Frage
Which of the following statements is true about casting?
Antworten
-
You must cast to convert from an interface type to a class type.
-
You must cast to convert from a class type to an interface type.
-
You cannot cast to convert an interface type to a class type.
-
You cannot cast from a class type to an interface type.
-
Both a and b above are true.
Frage 8
Frage
Which of the following statements is true about dynamic binding?
Antworten
-
Dynamic binding occurs during compile time.
-
Dynamic binding occurs when the appropriate overloaded method is selected.
-
Dynamic binding is another name for early binding.
-
In dynamic binding, the virtual machine selects the appropriate method.
-
Dynamic binding occurs only when an interface declares public static final constants.
Frage 9
Frage
Which of the following statements about interfaces is not true?
Antworten
-
An interface can specify constants that can be used by all classes that implement the interface.
-
An interface can specify variables that can be used by all classes that implement the interface.
-
An interface can specify methods that must be defined by all classes that implement the interface.
-
An interface name cannot be instantiated.
-
The interface contains declarations but not implementations.
Frage 10
Frage
Suppose foo is an object of class C, and C implements the interface type I. Which of the following statements must be true?
Antworten
-
foo was constructed with the constructor of I.
-
C assigns values to all constants declared in the interface I.
-
C supplies an implementation for all methods of the interface I.
-
foo must be declared as I foo = new C();
-
All methods of I are declared as private.
Möchten Sie mit GoConqr kostenlos Ihre eigenen Quiz erstellen? eigenen Mehr erfahren.