Unit 8: 2D Array

Question 1

A 2D array is ___.

Answer 1

an array of arrays

note: can put arrays in there or put names of already declared arrays

Question 2

declaring a 2D array (2 ways):

Answer 2

dataType[] arrayName = new dataType[row][column]

OR int[] arrayName = {{1, 2, 3}, {4, 5, 6]]

Question 3

how to find the number of rows and columns

Answer 3

rows = array.length
columns = array[0].length
(this is because APCSA only uses rectangular 2D arrays)

Question 4

accessing elements in an array

Answer 4

arrayName[row][column]

Question 5

setting elements to a value in an array

Answer 5

arrayName[row][column] = value;