Arrays

Question 1

What is an array

Answer 1

a data structure

a sequence of things all collected together

it is the most basic type of ‘list’

Lists of Primitives and Objects are slightly different

Question 2

What would be the syntax to create an int array called ‘myIntArray’of 6 values long?

Answer 2

int[] myIntArray = new int[6];

= 0 0 0 0 0 0
(currently all values in the array are 0)

type[] = new type[No.ofElements]

Question 3

Is an array an object?

Answer 3

YES

Question 4

What is myIntArray?

Answer 4

it is a reference

therefore, can have multiple references to the same array and can pass arrays to methods

Question 5

which loop works very well with arrays?

Answer 5

FOR loops:

• print all the elements in the array
• set the elements in the array
• look for a particular element in an array
• sort an array

Question 6

What does this code do?

public static void main(String[] args) {

int [] myIntArray = new int[6];
for(int i=0;
i

Answer 6

It sets the 2nd position

Question 7

What is an interface?

Answer 7

it defines a set of methods

Question 8

If a class implements an interface, it must implement…?

Answer 8

the methods in the interface

e.g. The interface called Comparable includes the compareTo method