NSC Information Technology Object-oriented programming: 5.1 Indicate whether the followi

Question

5.1 Indicate whether the following statements are TRUE or FALSE. Write only 'true' or 'false' next to the question numbers (5.1.1 to 5.1.3 in the ANSWER BOOK).

5.1.1 An array can only store elements of the same data type.
5.1.2 The index value for the first element in a Delphi array is always one.
5.1.3 The value 23 will be displayed in the rich edit component when the following code is executed:

var
  arrNumbers : array[1..5] of Integer = (4,2,3,1,8);
  iValue : Integer;
begin
  iValue := arrNumbers[2] + arrNumbers[3];
  Output.Lines.Add(IntToStr(iValue));
end;

5.2 The following algorithm written in pseudocode has been provided to enter integer values into variable A and B, swap the contents of the two variables and display A and B:

Input A
Input B
Temp <- A
A <- B
B <- Temp
Display A
Display B

5.2.1 What will be displayed if the value of 5 is entered into variable A and the value of 6 is entered into variable B?

5.2.2 Rewrite the algorithm so that the content of the variables will be swapped correctly.

5.3 A group of friends gathers once a week to have dinner at a local restaurant. They throw a six-sided dice three times to decide what type of meal they will have.

The following rules apply:
- If the number of the first throw is larger than the number of the second throw, they will eat chicken, or else
- If the number of the third throw is less than the number of the first throw, they will eat fish, or else
- They will eat burgers.

The following incomplete Delphi solution is provided for the scenario above:

var
  iFirst, iSecond, iThird: Integer;
sMeal: string;
begin
  iFirst := InputBox('Enter value of first throw', '', '');
  iSecond := InputBox('Enter value of second throw', '', '');
  iThird := InputBox('Enter value of third throw', '', '');
  sMeal: string;
  showMessage(sMeal);
end;

// Complete the program (Question 5.3.2)

5.3.1 Explain why a syntax error will be displayed when the provided part of the program is executed.

5.3.2 Complete the missing part for the program provided, to assign the correct type of meal to the sMeal variable according to the rules in the scenario above.

Assume that the syntax error referred to in QUESTION 5.3.1 has been corrected.

5.3.3 Which sequence of throws (A, B, C or D) will result in the group of friends having burgers as a meal?

5.4 The following UML (unified modelling language) class diagram represents a magazine object.

Magazine
- fMagazineID: Integer
- fTitle: string
- fPublisher: string
- fDatePublished: TDate
- fNumCopies: Integer
+ calculateCost()
+ setNumCopies()

5.4.1 Give TWO reasons why an UML diagram is an important OOP modelling tool.

5.4.2 What is the purpose of an accessor method?

5.4.3 Give an example of a mutator method in the given class diagram.

5.1 Indicate whether the following statements are TRUE or FALSE - NSC Information Technology - Question 5 - 2021 - Paper 2

Worked Solution & Example Answer:5.1 Indicate whether the following statements are TRUE or FALSE - NSC Information Technology - Question 5 - 2021 - Paper 2

5.1.1 An array can only store elements of the same data type.

5.1.2 The index value for the first element in a Delphi array is always one.

5.1.3 The value 23 will be displayed in the rich edit component when the following code is executed.