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5.1 You have been asked to assist in creating an application to control a smart television set (TV) - NSC Information Technology - Question 5 - 2024 - Paper 2
Question 5
5.1 You have been asked to assist in creating an application to control a smart television set (TV). The GUI below has already been designed. Identify TWO different... show full transcript
Worked Solution & Example Answer:5.1 You have been asked to assist in creating an application to control a smart television set (TV) - NSC Information Technology - Question 5 - 2024 - Paper 2
Step 1
Identify TWO different types of components on the GUI above which can be replaced with more suitable components and motivate why.
Answer
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The 'Select channel' edit box can be replaced with a combo box (or spin edit) to prevent users from typing in unintended values. This enhances user input control and ensures that only valid channel numbers can be selected.
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The 'TV volume' radio group can be replaced with a slider (or spin edit) to provide a more user-friendly interaction for adjusting volume levels. A slider allows users to easily see and control the volume visually.
Step 2
Explain the purpose of the AssignFile-statement with specific reference to the two arguments tFile and 'countries.txt'.
Answer
The AssignFile statement links the internal file variable 'tFile' to the external file 'countries.txt'. This sets up a connection between the program and the file on disk, allowing for input/output operations to be performed on 'countries.txt'. Essentially, it prepares the variable for subsequent operations like reading from or writing to the file.
Step 3
Explain why an error will occur if the Reset(tFile) in the given code is replaced with Append(tFile).
Answer
Using Append(tFile) implies that the program is trying to open 'countries.txt' for writing, which requires the file to already exist. If 'countries.txt' is not available (for instance, if it is a new file), this would result in an error, as Append cannot create a new file.
Step 4
Explain why no output will be displayed if Reset(tFile) is replaced with Rewrite(tFile).
Answer
The Rewrite(tFile) statement opens the file for writing and erases any existing content. As a result, when the program attempts to read from the file after it has been rewritten (which clears its content), there will be no data to output, leading to an empty display.
Step 5
Complete the pseudocode by writing down the remainder of the steps to solve the problem.
Answer
Step 3: Initialize HCF to 1. Step 4: While iLower > 0 do Step 5: If (iLower divides iUpper) then Step 6: Set HCF to iLower. Step 7: Break the loop. Step 8: If (iUpper > iLower) then Step 9: Set iUpper = iUpper - iLower. Step 10: Else Step 11: Set iLower = iLower - iUpper. Step 12: End while and display HCF.
Step 6
Which line of code will ensure that the names are sorted in alphabetical order?
Answer
Line 7 ensures that the names are compared correctly. Specifically, the conditional statement checks if 'arrNames[i]' is greater than 'arrNames[i + 1]'. If this condition holds true, it indicates that the names are out of order and need to be swapped.
Step 7
Explain why a runtime error will occur if the value of 1 is not provided from the length of the array in line 5.
Answer
If the value of 1 is not provided from the length of the array, the loop will attempt to access an array index that does not exist, leading to an out-of-bounds error. This could happen if the length of 'arrNames' is 0 or less than 2.
Step 8
Discuss the purpose of line 9 to line 11 of the provided code by explaining what the code does.
Answer
Lines 9 to 11 facilitate the swapping of array elements to sort them in ascending order. Specifically, line 9 assigns the value of the next element in the array (arrNames[i + 1]) to a temporary variable (sTemp). Line 10 then moves the current element (arrNames[i]) to the position of the next element. Finally, line 11 places the value stored in sTemp into the current position, effectively swapping the two elements if they were out of order.