An abstract class is which of the following?

A A class that has direct instances, but whose descendants may have direct instances.
B A class that has no direct instances, but whose descendants may have direct instances.
C A class that has direct instances, but whose descendants may not have direct instances.
D A class that has no direct instances, but whose descendants may not have direct instances

Correct Answer: A class that has no direct instances, but whose descendants may have direct instances.

Bissoy MCQ
#Database #Object Oriented Data Modeling

Related Questions

Which of the following declares an abstract method in an abstract Java class?
A public abstract method();
B public abstract void method();
C public void abstract Method();
D public void method() {}
E public abstract void method() {}
Atleast how many abstract methods must an abstract class contain?
A None
B One
C Two
D Five
Which of the following class definitions defines a legal abstract class?
A class A { abstract void unfinished() { } }
B class A { abstract void unfinished(); }
C abstract class A { abstract void unfinished(); }
D public class abstract A { abstract void unfinished(); }
The ratio of boys to girls in class A is 3 to 4 . The ratio of boys to girls in class B is 4 to 5 . If the two classes were combined, the ratio of boys to girls in class B is two less than the number of girls in class A. How many girls are in class A?
A 87
B 11
C 12
D 15
Three maths classes: X, Y, and Z take an algebra test. The average score of class X is 83. The average score of class Y is 76. The average score of class Z is 85. The average score of class X and Y is 79 and the average score of class Y and Z is 81. What is the average score of the combined classes X, Y, and Z?
A 81
B 81.5
C 82
D 84.5
Which one of the following keywords is used to define an abstract class?
A extends
B implements
C abstract
D new
How many instances of an abstract class can be created?
A 1
B 2
C 13
In Java, declaring a class abstract is useful
A To prevent developers from further extending the class.
B When it doesn't make sense to have objects of that class.
C When default implementations of some methods are not desirable.
D To force developers to extend the class not to use its capabilities.
E When it makes sense to have objects of that class.
Half the graduating class of a college was accepted by a business school. One-third of the class was accepted by a law school. It one-fifth of the class was accepted by both types of school, what fraction of the class was accepted only by a law school?
A 2/15
B 1/6
C 1/3
D 1/2
At the beginning of a class period, half of the students in a class go to the library. Later in the period, half of the remaining students go to the computer lab. If there are 5 students remaining in the class, how many students were originally in the class?
A 12
B 16
C 24
D 32

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