5.1 Procedures and functions are coding constructs often used as part of modular programming - NSC Information Technology - Question 5 - 2022 - Paper 2

A significant difference is that a procedure does not necessarily return a value, whereas a function must return a value. This distinction makes functions particularly useful for computations and operations that need to provide a result to the caller.

The statement is invalid. The assignment in programming languages should assign values correctly respecting the data types, and in this case, it attempts to assign a Boolean expression to a variable of a boolean type, which is incorrectly structured.

The statement is valid. Assuming Name1 and Name2 are string type variables, they can be compared using relational operators; hence this statement is valid.

Defensive programming is a coding practice aimed at ensuring the software continues to function under challenging conditions. It involves anticipating potential errors and programming safeguards to prevent these errors from causing undue program failures.

One possible reason for an overflow error is when a value is being stored in a variable, and that value exceeds the allowable range for the data type, such as trying to store a value larger than what an integer can hold.

To prevent runtime errors, programmers can implement data validation techniques. For example, checking if the input values fall within the allowable range before executing operations can avoid potential errors.

The primary purpose of a constructor method is to instantiate, create, or initialize an object, ensuring that all necessary starting values for the object's properties are set when the object is created.

The accessor method identified in the class diagram is 'getCompanyName():String', which is used to retrieve the value of the CompanyName attribute without modifying it.

The attribute 'CompanyNum' would have the least application for a mutator method since it uniquely identifies the company and should remain constant once set.

Modifying 'CompanyNum' using a mutator would undermine its role as a unique identifier for the company. It is crucial for maintaining data integrity and consistency within the system.

The class diagram indicates that certain attributes, such as 'CompanyName' and 'NumberOfEmployees', are public, which violates the principle of encapsulation. Access to these attributes should be restricted to provide better control over how they are modified.

Incorrect access can lead to unintentional modification of critical data attributes, resulting in inconsistencies or errors throughout the program. For instance, if 'CompanyName' can be changed freely, it may lead to misrepresentation of data within the application.

A sentinelled or conditional loop is preferably used when the number of iterations is unknown beforehand. This allows the program to keep looping until a specific condition is met, offering greater flexibility.

The code using a WHILE loop can be rewritten as follows:

  iNumber := RandomRange(1,11);
  While (iNumber = 5) OR (iNumber = 8) do
  begin
      iNumber := RandomRange(1,11);
  end;