Data Types & Records (Cambridge International AS Computer Science): Exam Questions

Refer to the insert for the list of pseudocode functions and operators.

A program will calculate the tax payable based on the cost of an item.

Calculations will occur at many places in the program and these involve the use of one of three tax rates.

Tax rate values represent a percentage. For example, a tax rate value of 5.23 represents 5.23%. In this case, the tax payable on an item costing $100 would be $5.23.

Tax rate values are used at several places within the program. One example is given in pseudocode as follows:

HighRate $\leftarrow$FALSE CASE OF ItemCost <= 50 : TaxRate$\leftarrow$3.75 // tax rate of 3.75% <= 200 : TaxRate$\leftarrow$5.23 // tax rate of 5.23% > 200 : TaxRate$\leftarrow$6.25 // tax rate of 6.25% HighRate$\leftarrow$TRUE ENDCASE TaxPayable $\leftarrow$ItemCost * TaxRate // tax payable

Give the appropriate data type for the variables in the following table, as used in the pseudocode:

The module to perform the checks and calculation will be implemented as a function. The function will need to return both a real and a Boolean value. To achieve this a record type is defined in pseudocode as follows:

TYPE Result DECLARE Done : BOOLEAN DECLARE Value : REAL ENDTYPE

The function Evaluate() will:

• take two parameters of type string representing the two numeric values

• return a variable of type Result with the Done field set to FALSE if either of the following applies:

  • at least one of the strings does not represent a valid numeric value
  • the numeric value of the string representing value y is zero

• otherwise return a variable of type Result with the Done field set to TRUE and the Value field assigned the result of the formula (based on the numeric value of the two parameters).

Write pseudocode for the function Evaluate().

To solve the error a programmer decides to create a new module.

The design of the new module has been completed and the module is being coded.

The new module referred to in part (c) introduces three new variables.

Complete the following table by giving the appropriate data type for each.

A program is being developed to implement a game for up to six players.

During the game, each player assembles a team of characters. At the start of the game there are 45 characters available.

Each character has four attributes, as follows:

The programmer has defined a record type to define each character.

The record type definition is shown in pseudocode as follows:

TYPE CharacterType DECLARE Player : INTEGER DECLARE Role : STRING DECLARE Name : STRING DECLARE Level : INTEGER ENDTYPE

The Player field indicates the player to which the character is assigned (1 to 6). The field value is 0 if the character is not assigned to any player.

The programmer has defined a global array to store the character data as follows:

DECLARE Character : ARRAY[1:45] OF CharacterType

At the start of the game all record fields are initialised, and all Player field values are set to 0

The programmer has defined a program module as follows:

Write pseudocode for module Assign().

Complete the table by giving the appropriate data type in each case.

A program is being developed to implement a game for up to six players.

During the game, each player assembles a team of characters. At the start of the game there are 45 characters available.

Each character has four attributes, as follows:

The programmer has defined a record type to define each character. The record type definition is shown in pseudocode as follows:

TYPE CharacterType DECLARE Player : INTEGER DECLARE Role : STRING DECLARE Name : STRING DECLARE SkillLevel : INTEGER ENDTYPE

The Player field indicates the player to which the character is assigned (1 to 6). The field value is 0 if the character is not assigned to any player.

The programmer has defined a global array to store the character data as follows:

DECLARE Character : ARRAY[1:45] OF CharacterType

At the start of the game all record fields are initialised, and all Player field values are set to 0

The programmer has defined a program module as follows:

Complete the pseudocode for module Count().

PROCEDURE Count(ThisPlayer : INTEGER, ThisRole : STRING)

A factory needs a program to help manage its production of items.

Data will be stored about each item.

The data for each item will be held in a record structure of type Component.

The programmer has started to define the fields that will be needed as shown in the table.

Write pseudocode to declare the record structure for type Component.

State three benefits of using an array of records to store the data for all items.

A record structure is declared to hold data relating to components being produced in a factory:

TYPE Component DECLARE Item_ID : STRING DECLARE Reject : BOOLEAN DECLARE Weight : REAL ENDTYPE

The factory normally produces a batch (or set) of 1000 components at a time. A global array is declared to store 1000 records for a batch:

DECLARE Batch : ARRAY [1:1000] OF Component

Two global variables contain the minimum and maximum acceptable weight for each component. The values represent an inclusive range and are declared as:

DECLARE Min, Max : REAL

When batches of less than 1000 components are processed, it is necessary to indicate that certain elements in the array are unused.

Suggest how an unused array element could be indicated.

Write pseudocode statements to declare the record data type FootballClub to hold data about football clubs in a league, to include:

• name of team
• date team joined the league
• main telephone number
• name of the manager
• number of members
• current position in the league.

Refer to the insert for the list of pseudocode functions and operators.

The following pseudocode represents part of the algorithm for a program:

CASE OF ThisValue < 30 : Level $\leftarrow$"Low" // less than 30 Check $\leftarrow$1 < 20 : Level $\leftarrow$"Very Low" // less than 20 Check $\leftarrow$ThisValue / 2 30 TO 40 : Level $\leftarrow$"Medium" // between 30 and 40 Check $\leftarrow$ThisValue / 3 Data[ThisValue]$\leftarrow$Data[ThisValue] + 1 > 40 : Level $\leftarrow$"High" ENDCASE

Give the appropriate data types for the variables ThisValue, Check and Level.

ThisValue ..........................................................................................................

Check ................................................................................................................

Level ...................................................................................................................

Refer to the insert for the list of pseudocode functions and operators

A shop sells car accessories. A customer order is created if an item cannot be supplied from current stock. A program is being developed to create and manage the customer orders.

The following identifier table shows some of the data that will be stored for each order.

Complete the identifier table by adding meaningful variable names and appropriate data types.

The data that needs to be stored for each customer order in part (a) is not all of the same type.

Describe an effective way of storing this data for many customer orders while the program is running.

Refer to the insert for the list of pseudocode functions and operators.

A program is being developed in pseudocode before being converted into a programming language.

The following table shows four valid pseudocode assignment statements.

Complete the table by giving the data type that should be used to declare the variable underlined in each assignment statement.

A structure chart shows the modular structure of a program:

The structure chart shows that Sub-9() is a function.

A Boolean value is returned by Sub-9() for processing by Module-A().

The original parameter RA is of type integer and RB is of type string.

A record type MyType will be defined with three fields to store the values passed between the two modules.

Write pseudocode to define MyType.