AP CSP Unit 3 Review

A program that Thomas has written is complete. It has been tested thoroughly, and some outputs were not as expected. Thomas is now going through the code carefully attempting to establish the cause of these errors and change the code to remove them. What is this procedure called?

• Error check

• Debugging

• Development

• Coding

Understanding of the life cycle of a program is an essential component to becoming an effective programmer. Which of the following is the best example of how the life cycle of a program should work?

• Idea→algorithm→write code→execute code→maintain→debug

• Idea→algorithm→write code→debug→execute code→maintain

• Idea→write code→algorithm→execute code→debug→maintain

• Idea→algorithm→write code→execute code→debug→maintain

Jeremiah is part of a group planning a summer fair at which local businesses can run stalls and events. He wants to use his programming skills to develop an app for the fair which businesses will be able to use to communicate information about their activities at the fair with visitors. Which of the following would be the best first step for Jeremiah to take?

• Develop all of the major algorithms which will be required for the app by drawing flowchart representations

• Write thorough documentation explaining how the code for the app works

• Write some sample code to understand how the app might work

• Find out from the businesses and potential visitors what information and format they think should be used for the app

Which of the following is the MOST important reason computers use artificial languages over natural language?

• The meaning of different characters and words in an artificial languages is explicit and unambiguous

• The syntax of natural languages is easy to translate by computers

• The syntax of artificial languages is explicit and unambiguous

• The meaning of different characters and words in an artificial languages is too complicated

Which of the following best describes high-level computing languages?

• They are not very ambiguous

• They are extremely difficult for humans to read and understand

• They evolve naturally over time

• They are very easy for machines to understand and parse

A statistics teacher wishes to create a program on her calculator that generates a random even integer. The command built in the calculator to generate a random positive integer is RANDOM(a,b). This command generates a random integer between integers a and b (and including a and b). Which of the following lines of code will ensure that the random integer generated will be even?

• RANDOM(a,b) + 1

• RANDOM(a,b) + 2

• RANDOM(a,b) * 2

• RANDOM(a,b) - 2

Consider the following actions which might be performed by a developer when creating a new piece of software to solve a problem.

1. Thoroughly testing code with a variety of inputs

2. Designing an algorithm to tackle the central problem the program hopes to solve

3. Considering what outputs a program solving the problem might produce and what inputs it may require to do this

4. Writing code in a high-level programming language to implement an algorithm

In which order in the development cycle would these actions first appear?

• 3, 2, 4, 1

• 2, 4, 1, 3

• 2, 3, 4, 1

• 3, 4, 1, 2

Tamara is writing code as part of a large project. She has just compiled her code and run it, but the result is not exactly as expected. Which of the following strategies would be efficient ways to “debug” her code so that it works as intended?

Select two answers.

• Add statements to display the state of the program at various points to try and identify where the error might have occurred.

• Continue to write code, but look for ways in which the error from this part of the program can be corrected or compensated for.

• Try changing some of the inputs to see under what circumstances the program is not working and what type of error may be occurring.

• Retype each statement in the program again, being extra careful not to make mistakes this time.

Which is NOT true about comments in programs?

• Commenting helps programmers develop and maintain programs to efficiently solve problems.

• Commenting helps while working collaboratively in programming environments.

• All published programs have their comments available.

• Commenting about program components helps in developing and maintaining programs.

A team of students is collaborating on a program to obtain local weather data from a website, and predict weather-related school closings based on their own formulas. They must present their code to a group of faculty, some of whom have little to no experience with code. What strategies can the group use while writing their code, in order to make it more understandable for the faculty?

Select two answers.

• Choose meaningful names for all variables and procedures.

• Include comments detailing previous, unsuccessful coding attempts.

• Include comments detailing the purpose and behavior of variables and procedures.

• Repeat blocks of code to emphasize their importance in the process.