4.4 Theory of Computation

Question 1

What is representational abstraction?

Answer 1

A representation arrived at by removing unnecessary details

Question 2

What is abstraction by generalisation?

Answer 2

Grouping by common characteristics to arrive at a hierarchical relationship of the ‘…is a kind of…’ type.

Question 3

What is procedural abstraction?

Answer 3

The result of abstracting away actual values to create a computational method, a procedure.

Question 4

What is functional abstraction?

Answer 4

A further abstraction of a functional abstraction, which disregards the particular computational method.

Question 5

Why do we use data abstraction?

Answer 5

It enables us to isolate how a compound data object is used from the details of how it is constructed.

Question 6

What is problem abstraction?

Answer 6

Removing details until the problem solves itself.

Question 7

What is decomposition?

Answer 7

Breaking a problem into a number of sub problems so that each sub problem accomplishes an identifiable task.

Question 8

What are the metacharacters used in regular expressions?

Answer 8

*   0 or more repetitions
\+   1 or more repetitions
?   0 or 1 repetitions
     ie, optional
|    alternation
     ie or
( )  to group regular 
     expressions

Question 9

What is the purpose of BNF?

Answer 9

To describe a programming language in a simple and concise manner