AP Computer Sci Principles unit 1

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?

• Devlopment

• Error Check

• Coding

• Debugging

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→write code→algorithm→execute code→debug→maintain

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

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

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

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

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

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

Consider the following two implementations of the same algorithm, each written in a different language.

Language A: Calculate the average daily rainfall for the week (averageRainfall) by adding together the rainfall totals for each of the 7 days of the week (sun, mon, tue, wed, thu, fri, and sat) and dividing the sum by 7.

Language B: Take the total amount of rain from each day of the week (sunday, monday, tuesday, wednesday, thursday, friday and saturday) and then average them together to get the average daily rainfall for the week (averageRainfall).

Which of the following statements about these two implementations is true?

• Neither of these languages is clear enough that a programmer could write a correct solution in a high-level programming language.

• Language A is ambiguous because it is unclear what sun, mon, tue, wed, thu, fri, and sat refer to in context with the problem.

• Language B is ambiguous because the process of “average” is not explained well

• The algorithms in both languages are ambiguous because they do not specify the actual values of the seven daily rainfall totals.

The algorithm below simulates rolling a regular 6-sided die twice. Consider the goal of determining if the sum of the values of the two rolls is odd or even.

 

Step 1: Using a random number generator, get a value between 1 - 6 inclusively Step 2: Remember that number Step 3: Repeat steps 1 and 2 Step 4: Add the two remembered numbers together Step 5: Multiply that sum by 10 Step 6: Divide the result of that multiplication by 2

 

What conclusions can be made with regard to what we are trying to determine? Select two answers:

• If the value found in step 6 is 10, 30 or 50 then the sum is odd

• If the last digit of the value found in step 6 is 5, then the sum is odd

• If the value found in step 6 is 10, 20, 30, 40, 50 or 60 then the sum is even

• If the value found in step 6 is not 20, 40, 60, 80, 100 or 120 then the sum is odd

Which of the following should be true of any algorithm?

I. The order in which the steps making up the algorithm are followed is logically determined II. Following the instructions in the algorithm will always result in the same outputs, regardless of any inputs III. The instructions in the algorithm contain all necessary information to be implemented

• II and III only

• I and III only

• I only

• I, II and III

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 too complicated

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

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

• The syntax of artificial languages is explicit and unambiguous

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

• They are very easy for machines to understand and parse

• They are extremely difficult for humans to read and understand

• They are not very ambiguous

• They evolve naturally over time

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) + 2

• RANDOM(a,b) - 2

• RANDOM(a,b) + 1

• RANDOM(a,b) * 2

Which of the following describes the part of a computer which stores instructions and information which has been input to the computer?

• RAM

• CPU

• Binary

• Machine Code