OOP Biweekly Test#1

1.

1 point

What does Moore's law predict?

Roughly every decade a new, lower priced computer class forms based on a new programming platform, network, and interface resulting in new usage and the establishment of a new industry

The current through a conductor between two points is directly proportional to the potential difference across the two points

Approximate doubling of computer power, for comparable price, every eighteen months

2.

1 point

A precondition is a

feature of the class

logical property associated with a particular feature

property that all objects of a certain class must obey to

logical property that must always hold

3.

1 point

A class is a

table of properties

description of features applicable to objects

collection of objects

description of a set of possible run-time objects to which the same features are applied

4.

1 point

A contract is a

(Check all that apply)

Description of a feature

Description of a class

Semantic condition characterizing usage properties of a class or a feature

Agreement signed by two participants dealing in business

5.

1 point

Assume, you have a feature defined as below:

my_feature (x: INTEGER) -- Line 01
require -- Line 02
validity_check: x >10 -- Line 03
do -- Line 04
…
end -- Line 05

What will happen if you remove line #02?

You will get a compilation error

You will get a run-time error

Compiler will output: “I am happy”

None of the above

6.

1 point

With respect to Design by Contract, when may a contract be violated?

An invariant check fails

A client invokes a routine satisfying its precondition, but the routine does not satisfy its postcondition

A feature is invoked without satisfying to its precondition

All mentioned above

7.

1 point

Assume we have feature 'f (x : INTEGER)' that requires the argument x to be a non-negative number.

How can be classified precondition 'pre1'?

f (x: INTEGER)

require
pre1: x > -10

sound and complete

unsound and incomplete

unsound and complete

sound and incomplete

8.

1 point

Assume we have feature 'f : INTEGER' that ensures returning a non-negative number.

How can be classified the postcondition 'post1' ?

f: INTEGER

ensure
post1: Result > -10

sound and incomplete

unsound and complete

sound and complete

unsound and incomplete

9.

1 point

Which of the following statements are true about deferred classes? (select all that apply)

It cannot be instantiated

It cannot have exported features

All the features of the deferred class should be deferred

They are required to introduce abstraction and capture common behavior

10.

1 point

A key for establishing loop’s correctness is

Feature

Attribute

Loop invariant

None of the above

11.

1 point

If you were asked to design and implement two classes representing geometric figures - Circle and Ellipse, how would you use inheritance?

Check all that apply.

Circle class inherits from Ellipse class

A Circle object would be a component of Ellipse class

Ellipse class inherits from Circle class

Both Circle and Ellipse should inherit from the same parent class

12.

1 point

The precondition of a redefined feature can only stay the same or be strengthened

True

False

13.

1 point

A class invariant in an descendant class can only stay the same or be strengthened

True

False

14.

1 point

What are the pillars of OOP?

Class

Inheritance

Encapsulation

Contract

Feature

Invariant

Polymorphism

OOP Biweekly Test#1 - BS1.1