Integrated Development Environment (IDE)

A student is writing a program in a high-level programming language.

The student writes the program using an Integrated Development Environment (IDE).

Complete the table by identifying and describing three features of an IDE that the student can use to debug their program.

The program the student is developing includes both global and local variables.

Explain the difference between a global variable and a local variable.

Describe one drawback of using global variables in a program.

Describe one drawback of using local variables in a program.

A variable can be passed as a parameter into a function by value or by reference.

Describe what parameter passing by value means.

An algorithm is needed to count how many times each of the numbers from 1 to 9 appear in an array called myArray. Another array called checked is used to store each number found in myArray and the number of times it appears. For example, the contents of myArray are:

Based on these contents in myArray, the contents in checked would be:

–1 indicates an unused space in the array as the numbers 1, 4, 8 and 9 have not been found.

The student has written the following pseudocode for this program.

The pseudocode contains several errors.

Identify the line number of any four errors and write the corrected line for each error.

Error 1

Error 2

Error 3

Error 4

7* (a) A program designer needs to decide on an algorithm to use from a choice of three. The table shows the worst-case Big O complexities for each algorithm.

The program will be used to analyse data that can range from 2 items to 2 billion items.

Compare the use of all three algorithms and suggest which the programmer should use.

You should include the following in your answer:

• the meaning of constant, logarithmic, linear and exponential complexity

• how well each algorithm scales as the amount of data increases

• which algorithm is the most suitable for the given task.

The program designer is investigating the use of concurrent processing.

Describe what is meant by the term ‘concurrent processing’.

Give two benefits of using concurrent processing.

The programmer needs to use a merge sort in one part of the problem to sort items in ascending order.

Describe how a merge sort works.

Give one benefit and one drawback of the programmer using a merge sort instead of a bubble sort.

The programmer uses an Integrated Development Environment (IDE).

Complete the table by identifying and describing three IDE features that can help the programmer to develop, or debug a program.

A computer program stores data in an array named words.

The data in the array needs to be searched for a value that the user inputs.

One example of a searching algorithm is a binary search.

Identify the precondition for a binary search.

A second example of a searching algorithm is a linear search.

Describe how a linear search works.

The array words is defined as a global variable and contains these values:

The pseudocode function useWords() here uses the global array words.

The number of words in the array words is passed as a parameter.

Identify two variables in the function useWords().

numberOfWords is a parameter passed by value.

Describe the difference between passing a parameter by value and by reference.

Rewrite the function useWords() to use a while loop instead of a for loop.

The function header and close have been written for you.

Write your answer using pseudocode or program code.

function useWords(numberOfWords: byVal)

endfunction

Give one benefit and one drawback of declaring the array as a global variable instead of a local variable.

Describe one feature of an Integrated Development Environment (IDE) that can be used to help write the program and one feature that can be used to help test the program.

Functions and procedures are reusable components.

Give two benefits of writing a program with reusable components.

4* Anna currently writes her program code in a text editor and then runs the compiler.

She has been told that using an Integrated Development Environment (IDE) would be more helpful.

Discuss the benefits of Anna using an IDE to write and test her program rather than using a text editor.

Barney is writing a program to store data in a linked list. He is writing the initial program for a maximum of 10 data items.

Each node in the linked list has a data value and a pointer (to the next item).

A null pointer is stored with the value –1.

Describe the purpose of freeListPointer.

State the purpose of headPointer.

Barney wants the nodes to be stored as objects using object-oriented programming. He designs the following class.

The constructor assigns the parameters to the attributes to create an object.

The class node, uses get methods and set methods.

Describe one difference between get methods and set methods.

The function findNodePath() takes the data item to find in the linked list as a parameter and follows the pointers to find the required node.

The function returns the array indexes of all the nodes it visits and joins this to a suitable message stating whether the data was found or not found and then returns this as one string.

Describe how the function findNodePath() will search for the data item and return the required message.

The procedure printLinkedList() follows the pointers to print all of the elements in the linked list.

The procedure has a number of errors.

Identify the line of each error and write the corrected line.

Error 1 line number........

Error 1 correction........

Error 2 line number........

Error 2 correction........

Error 3 line number........

Error 3 correction........

Barney will use an Integrated Development Environment (IDE) to debug his program code.

Describe three features commonly found in IDEs that Barney could use to debug his program code.

* Barney would like his linked list to be part of a base program that is saved in a library. This means that it can be reused and changed by other programs.

Discuss the benefits of using different object-oriented techniques that Barney could use to achieve this.

Mabel is a software engineer. She is writing a computer game for a client. In the game the main character has to avoid their enemies. This becomes more difficult as the levels of the game increase.

Mabel uses decomposition to design the program.

Explain how decomposition can aid the design of this program.

The computer game allows a user to select a character (e.g. name, gender). They can then choose a level for the game (easy, normal, challenging). The user controls their character by moving it left or right. The character can jump using space bar as an input. If the character touches one of the enemies then it loses a life. The character has to make it to the end of the level without losing all their lives.

The game is designed in a modular way.

One sub-procedure will handle the user input.

Describe three other sub-procedures Mabel could create for the given game description.

Describe the decision that the program will need to make within the user input sub- procedure and the result of this decision.

Define pipelining and give an example of how it could be applied in the program.

*Mabel has been told that true programmers write programs in a text editor, and do not use IDEs. Mabel does not agree with this statement.

Discuss the use of an IDE in the development of this program.

A programmer is developing an ordering system for a fast food restaurant. When a member of staff inputs an order, it is added to a linked list for completion by the chefs.

Explain why a linked list is being used for the ordering system.

Order 158 has been made, and needs adding to the end of the linked list.

Add the order, 158, to the linked list as shown in Fig. 2.1. Show the contents of the linked list in the following table.

Order 159 has been made. This order has a high priority and needs to be the second order in the linked list. Add the order, 159, to the original linked list as shown in Fig. 2.1. Show the contents of the linked list in the following table.

The linked list is implemented using a 2D array, theOrders:

• Row 0 stores orderNo

• Row 1 stores next

The data now stored in theOrders is shown in Fig. 2.2.

The following algorithm is written:

Outline why nodeNo does not need to be stored in the array.

Complete the trace table for procedure x, for the data shown in Fig. 2.2.

Describe the purpose of procedure x.

A new order, 190, is to be added to theOrders. It needs to be the third element in the list. The current contents of the array are repeated here for reference:

Describe how the new order, 190, can be added to the array, so the linked list is read in the correct order, without rearranging the array elements.

The user needs to be able to search for, and find, a specific order number.

State an appropriate search algorithm that could be used, and justify your choice against an alternative Search algorithm.

Appropriate Search Algorithm........

The programmer is writing the program using an IDE.

Identify three features of an IDE that the programmer would use when writing the code and describe how the features benefit the programmer.

(f*) The programmer is considering using concurrent programming.

Discuss how concurrent programming can be applied to the food ordering system and the

benefits and limitations of doing so.