AP Computer Science Principles Unit 4 Review

Which of the following is an advantage that text-based programming languages (e.g., Processing) have over block-based programming languages (e.g., Scratch)?

• Text-based programming languages allow programmers to write programs in English and other natural languages.

• Text-based programming languages do not require the programmer to worry about syntax, capitalization, or punctuation.

• Programs written in text-based programming languages do not require debugging.

• Text-based programming languages offer programmers more detailed control over lower-level functionality when writing a program.

Consider the above procedure. Which of the following best describes the behavior of the find procedure?

• Displays the position of the first occurrence of target in list

• Displays the positions of all occurrences of target in list

• Displays the position of the last occurrence of target in list

• Displays each item in list that is equal to target

Consider the following algorithm for manipulating the individual pixels of a digital, RGB image of a panda bear surrounded by dense, green jungle foliage.

Algorithm: For each pixel, swap the values in the green and blue channels, leaving the red channel alone.

Which of the following best describes the resulting image?

• The panda’s fur will appear red and black.

• The foliage will appear green, but the panda’s fur will appear blue and black.

• The panda’s fur will appear black and white, but the foliage will appear to be tinted blue.

• The resulting image will look identical to the original, unmodified image.

• The resulting image will be a grayscale version of the original image.

• The overall brightness of all pixels in the resulting image will be darkened.

• The resulting image will be completely white.

• All of the colors of the resulting image will be inverted, like a negative, of the

  original image.

A programmer complete the user manual for a video game she has developed and realizes she has reversed the roles of “goats” and “sheep” throughout the text. Consider the programmer’s goal of changing all occurrences of “goats” to “sheep” and all occurrences of “sheep” to “goat.” The programmer will use the fact that the word, “foxes” does not appear anywhere in the original text. Which of the following algorithms can be used to accomplish this?

• First, change all occurrences of “goat” to “sheep” and then change all occurrences of “sheep” to “goat”

• First, change all occurrences of “goat” to “sheep,” then change all occurrences of “sheep” to “foxes” and then change all occurrences of “foxes” to “goats”

• First, change all occurrences of “goat” to “foxes,” then change all occurrences of “sheep” to “goat” and then change all occurrences of “foxes” to “sheep”

• First, change all occurrences of “goat” to “foxes,” then change all occurrences of “foxes” to “sheep” and then change all occurrences of “sheep” to “goats”

In order to be inducted into a school’s National Honor Society (NHS), they must meet certain criteria for their GPA, serviceHours and grade. The expression below indicates whether a student has been accepted as a member of the NHS.

(GPA = 3.65) AND (serviceHours = 30) AND (NOT grade = 9)

Which of the following values would indicate a student that would be accepted into NHS?

• GPA = 3.85, serviceHours = 45, grade = 9

• GPA = 3.50, serviceHours = 100, grade = 10

• GPA = 4.00, serviceHours = 15, grade = 11

• GPA = 3.65, serviceHours = 30, grade = 12

Which of the following is true about program documentation?

• Program documentation is only needed for programs in development; it is not needed after a program is completed.

• Program documentation is useful when programmers collaborate but not when a programmer works individually on a project.

• Program documentation is useful during initial program development and also when modifications are made to existing programs.

• Program documentation should not be changed after it is first written.

A student is recording a song on her computer. When the recording is finished, she saves a copy on her computer. The student notices that the saved copy is of lower sound quality than the original recording. Which of the following could be a possible explanation for the difference in sound quality?

• The song was saved using fewer bits per second than the original song.

• The song was saved using more bits per second than the original song.

• The song was saved using a lossless compression technique.

• Some information is lost every time a file is saved from one location on a computer to another location.

Which of the following are benefits of using well-named variables in a computer program?

Select two answers.

• The program will run faster.

• The program will be easier for people to read.

• The program will have a greater data storage capacity.

• The program will be easier to modify in the future.

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