APCSA Unit 8 Study Quiz

What Are 2D Arrays

• 2D arrays are arrays of strings. They represent words and strings of an object

• 2D arrays are arrays of integers. They represent an array of integers

• 2D arrays are arrays of objects. They also have the function of storing values from the object

• 2D arrays are arrays of arrays. They also have the function of storing data like arrays

How Do You Access An Array Element In 2D Arrays

• You use bracket notation array[row_index][column_index]

• You use bracket notation

  array[row_index, column_index]

• You use parenthesis notation

  array(row_index)(column_index)

• You use hard brackets array{row_index, column_index}

What Do You Need To Access/Update An Element Of A 2D Array

• Name of any variable

  Two sets of brackets

  The index of the location of the row

  The index of the location of the column

• Name of the object

  Two sets of parenthesis

  Row index.

  Row index

• Two sets of periods

  Column index and column index

• Row index and element index

How Do You Traverse 2D Arrays

• Using a single loop to iterate over both rows and columns
• Using nested loops to iterate over rows and columns
• Using recursion to traverse each element individually
• Using a while loop to iterate over rows and columns

How Do You Use For Loops In Traversing 2D Arrays

• for (int i = 0; i < columns; i++) { for (int j = 0; j < rows; j++) { // Access array element at position (i, j) }}
• for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { // Access array element at position (j, i) }}
• for (int i = 0; i < rows; i++) { for (int j = 0; j < columns; j++) { // Access array element at position (i, j) }}
• for (int i = 0; i < rows; i++) { for (int j = 0; j < rows; j++) { // Access array element at position (i, j) }}

How Do You Use Enhanced For Loops In 2D Arrays

• Enhanced for loops cannot be used with 2D arrays
• 2D arrays do not support iteration
• Enhanced for loops in 2D arrays require a specific library
• Nested for loops are used to iterate over each element in a 2D array using enhanced for loops.

Consider the following two-dimensional array words.

String[][] words = { {"about", "actor", "admit", "agile"},

{"badge", "basic", "berry", "bingo"},

{"cacti", "cedar", "chair", "close"}};

What is the fifth element visited when column-major traversal is performed on words?

• about

• agile

• badge

• basic

• cedar

What Is The Row-Major Traversal In 2D Arrays

• Row-major traversal in 2D arrays means accessing elements row by row.
• Row-major traversal refers to accessing elements randomly.
• Row-major traversal involves accessing elements diagonally.
• Row-major traversal means accessing elements column by column.

What Is Column-Major Traversal In 2D Arrays

• Column-major traversal is not applicable in computer science.
• Column-major traversal is used in 1D arrays only.
• Column-major traversal is also known as 'column-wise' traversal.
• Column-major traversal is also known as 'row-wise' traversal.

Consider the following two-dimensional array words.

String[][] words = { {"about", "actor", "admit", "agile"},

{"badge", "basic", "berry", "bingo"},

{"cacti", "cedar", "chair", "close"}};

What is the fifth element visited when row-major traversal is performed on words?

• about

• agile

• badge

• basic

• cedar