Unit 8 - AP Computer Science Flashcards

Questions and Answers

Which of the following code segments can be used to correctly create and initialize myArray?

int myArray[][] = {{0, 0, 3}, {0, 0, 0}, {7, 0, 0}}; (correct)

int myArray[][] = new int[3]; myArray = 3; myArray = 7;

int myArray[][] = new int; myArray = 7; myArray = 3;

Which of the following initializer lists could replace so that the code segment will work as intended?

{{0, 1, 2}, {4, 5, 6}, {8, 3, 6}} (correct)

{{1, 3, 2}, {4, 5, 7}, {8, 3, 6}}

Which of the following can replace so that the code segment works as intended?

System.out.println(keyboard);

keyboard + keyboard + keyboard (correct)

Which of the following code segments properly declares and initializes twoD so that the code segment works as intended?

String[][] twoD = { {"V", "AV", "J"}, {"JA", "VA", "A"}, {"JA", "J", "JAV"}, {"AV", "V", "A"}}; Signup and view all the answers

As a result of executing the code segment, how many times are 'Condition one' and 'Condition two' printed?

'Condition one' is printed once, and 'Condition two' is printed twice. Signup and view all the answers

How many times will the statement in line 11 be executed as a result of executing the code segment?

2 Signup and view all the answers

For which of the following two-dimensional array input values does sumRows NOT work as intended?

{{4, 1, 7}, {-10, -11, -12}} Signup and view all the answers

Which of the following values for num can be used as a test case to show that the code segment does not work as intended?

15 Signup and view all the answers

Study Notes

Two-Dimensional Arrays

A two-dimensional array can be created and initialized using syntax such as int[][] myArray = {{0, 0, 3}, {0, 0, 0}, {7, 0, 0}}.
To access elements in a 2D array, use array[row][column] notation.

Code Segments and Initializers

An initializer list such as {{0, 1, 2}, {4, 5, 6}, {8, 3, 6}} can be used to populate arrays based on even and odd column index criteria.
Java requires specific syntax to create and initialize 2D arrays, ensuring all elements are defined within brackets.

Printing from 2D Arrays

To print values from a 2D array, verify that the correct variable or concatenation method is used, e.g., printing elements with System.out.println() for required output.

String Arrays and Display

Strings can be stored in a 2D array and printed in a specific order by iterating through the array dimensions.

Conditional Statements in Nested Loops

In nested loops, conditions like checking modulo values influence the execution of statements multiple times based on index evaluations, e.g., "Condition one" and "Condition two" being printed based on specific criteria.

Array Manipulation

An integer array can be modified conditionally; for instance, incrementing even values within the array affects the outcome when assessing maximum values.
Perform checks to ensure that modifications to array elements occur within valid bounds without errors.

Method Iteration and Summation

Custom methods can traverse arrays to calculate sums, but may fail if array dimensions are mismanaged or if assumptions about row lengths are incorrect.
Consider input arrays such as {{4, 1, 7}, {-10, -11, -12}} that may break intended functionality in methods summing elements.

Finding Array Element Indexes

To find the position of an element in a 2D array, ensure that loop boundaries are set correctly to avoid skipping elements or out-of-bounds errors.
Test with values like 15 to confirm that indexing logic is functioning properly.

Practical Implementation

Understanding and implementing these concepts in tasks will require knowledge of loop structures, conditionals, and array basics in Java programming.

Description

Test your knowledge on two-dimensional arrays and their initialization in this AP Computer Science Unit 8 flashcard quiz. Assess your understanding of array creation and Java syntax through multiple-choice questions. Perfect for students preparing for the AP exam!