Module 3: Arrays

Question 1

What is an Array?

Answer 1

An array stores multiple values in a single variable.

Ex:

int[] numbers = {1,2,3,4,5};

Question 2

How do you loop through an array?

Answer 2

1. Using a for - each loop (preferred way).

Ex:

int[] numbers = {1,2,3,4,5};
for(int x: numbers) {System.out.println(x);}

2. Using the .length property in a for loop.

Ex:

int[] numbers = {1,2,3,4,5};
for(int x=0; x<numbers.length; x++)
{System.out.println(numbers[x]};

Question 3

What is a multidimensional array?

Answer 3

An array of arrays.

Ex:

int[][] groups = {{1,2,3}, {4,5,6}};

Question 4

How do you loop through a multidimensional array?

Answer 4

1. Using a nested for - each loop (preferred way).

Ex:

int[][] numbers = {{1,2,3,4}, {5,6,7}};
for (int[] row: numbers) {for (int i : row)
{System.out.println(i);}}

2. Using the .length property in nested a for loop.

Ex.

int[][] numbers = {{1,2,3,4}, {5,6,7}};
for(int x=0; x<ages.length; x++) {for(int y=0; y<ages[x].length; y++) {System.out.println(ages[x][y]);}}