Pass Task 5.2: Arrays of Records
Overview
In many programs you will want to store a number of values, where each of those values is a record.
Purpose: Learn how to declare and work with arrays of records.
Task: Extend your records program (Pass Task 4.1) to use arrays.
Instructions
In this task you will extend your program from Pass Task 4.1 to add an array of the record you have already created. The program can then populate an array of values for the user, output these values, and output some additional summary data.
You will need to make the following changes.
- Create a procedure to populate an array of your records from user input via the terminal.
- Create a print all procedure to print all of the records from an array.
- Create a procedure to add a value to your array.
- Create a function to calculate summary data from your records.
- Adjust Main to store a dynamic array of values, read in the number of values the user wants to enter, and set the length of the array, and then show the user a menu. For example:
procedure: Main
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Local Variables:
- addressBook : a dynamic array of ContactData
- numContacts : an Integer for the number of contacts
- option : an Integer for the user's choice from the menu
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Steps:
1: Assign numContacts, the result of calling ReadInteger( 'Enter initial number of contacts: ')
2: Set the Length of addressBook to be numContacts 3: Call Populate Contacts and pass in the addressBook 4: Repeat...
5: Output a menu '1: Add another contact,
2: Print all contacts, 3: Find a contact,
4: Quit'
5: Assign option, the result of calling ReadInteger( 'Enter option: ')
6: In the case when option is 1:
Call Add Contact, with reference to addressBook 7: In the case where option is 2:
Call Print Contacts and pass in the addressBook 8: In the case where option is 3:
Output 'Has contact: ', and the result of HasContact( addressBook,
ReadString('Which contact name: ') ) 9: Until option equals 4
Notes on the following pages indicate the summary data you should calculate for your program based on the different options you may have chosen in Pass Task 4.1.
Adding a New Value to the Array
For all program options, you will need to create a procedure to add a new value into your ar- ray. The following pseudocode demonstrates how this can be achieved for the Address Book program.
procedure: Add Contact
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Parameters:
- contacts : a reference to a dynamic array of ContactData
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Steps:
1: Call SetLength, of contacts, Length(contacts) + 1
2: Assign the last contact, the value of Read Contact('Enter new contact details')
In Pascal you will need to create your own type to represent the dynamic array. For example, the above pseudocode would need to be coded as follows, with ContactArray being the dy- namic array of contacts:
Option 1: Cost Calculator
Allow users to Add Expense to the program, and use the following function to calculate the total of all of the expenses of a certain kind.
function: Total Expense
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Parameters:
- expenses : a constant reference to an array of ExpenseData
- kind : an Expense Kind
Returns (result):
- An Integer with the sum of all the expenses' costs with the matching kind
Local Variables:
- i : an Integer
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Steps:
1: Assign result, the value 0
2: For each element of expenses (i := 0 to High(expenses))
3: If the ith expense's kind equals kind
4: Assign result, the value of result + the ith expenses' cost
Add a second function named Largest Expense Of Kind to find the largest expense of a cer- tain kind.
Create a menu that allows the user to:
1. Add another expense
2. Print all expenses
3. Print total expense for a kind
4. Print largest expense for a kind
5. Quit
Option 2: Instrument Readings
Allow users to add Readings, and use the following function to calculate the average of all of the readings of a certain kind.
function: Average Reading
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Parameters:
- readings : a constant reference to an array of SensorData
- kind : a Sensor Kind
Returns (result):
- A Double with the average of all the readings' values with the matching kind
Local Variables:
- i : an Integer
- numReadings : an Integer
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Steps:
1: Assign result, the value 0
2: Assign numReadings, the value 0
3: For each element of readings (i := 0 to High(readings)) 4: If the ith reading's kind equals kind
5: Assign result, the value of result + the ith reading's value
6: Increase numReadings by 1 7: If numReadings is larger than 0
8: Assign result the value result / numReadings
Add a second function named Largest Reading Of Kind to find the largest reading of a cer- tain kind.
Create a menu that allows the user to:
1. Add another reading
2. Print all readings
3. Print average reading for a kind
4. Print largest reading for a kind
5. Quit
Option 3: High Scores
Use the following function to calculate the highest score for a player.
function: Average User Score
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Parameters:
- scores : a constant reference to an array of Game Score Data
- name : a String Returns (result):
- A Integer with the highest score for the player from scores Local Variables:
- i : an Integer
- numScores: an Integer
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Steps:
1: Assign result, the value 0
2: Assign numScores, the value 0
3: For each element of scores (i := 0 to High(scores)) 4: If the ith score's user name equals name
5: Assign result, the value of result + the ith score's value
6: Increase numScores by 1 7: If numScores is larger than 0
8: Assign result the value result / numScores
Add a second function named Highest User Score to find the highest score for a given user name.
Create a menu that allows the user to:
1. Add another score
2. Print all scores
3. Print average user score for a user
4. Print highest score for a user
5. Quit
Option 4: Bounty Hunter's Hit List
Use the following function to calculate the highest value hit of a certain kind.
function: Most Valuable Hit
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Parameters:
- targets : a constant reference to an array of Target Data
- kind : a Difficulty Kind Returns (result):
- A Target Data with the highest value for the given kind Local Variables:
- i : an Integer
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Steps:
1: Assign result, a default value (i.e. set its value to 0, difficulty to the kind parameter, and name to 'No match')
2: For each other element of targets (i := 0 to High(targets))
3: If (the ith target's kind) equals kind) and ( the jth target's value is larger than the result's value )
4: Assign result, the value of the ith target
Add a second function named Average Hit Kind Value to find the average value of hits of a certain kind.
Create a menu that allows the user to:
1. Add another hit
2. Print all hits
3. Print most valuable hit for a kind
4. Print average value of a hit for a kind
5. Quit
Option 5: Make your own...
Use the above four declarations guide you to extend your own program. The functions should accept the array and some other value and loop through the array to calculate some summary value (sum, count, average, min, max, etc).
Add two functions to calculate values from the data you collected.
Attachment:- problem.pdf