Coding - practical 10

Question 1

What do arrays allow us to do?

Answer 1

Arrays allow us to group together a number of variables in a single statement.

Question 2

Give an example of an array for 4 note numbers.

Answer 2

std::array  notes; 
(instead of)
int note1;
int note2;
int note3;
int note4;

Question 3

What is the general form of an array?

Answer 3

1. Variable type (e.g. std::array)
2. Template initialisation ()
3. Name of our array (notes;)

Question 4

Describe template initialisation.

Answer 4

Template initialisation is basically a way to tell the compiler what kind of array we want.

• The triangle brackets ( < > ) are used to tell the compiler what kind of array you want.
• Within this is the type (e.g. int) and size (e.g. 4)

Question 5

What is reading and writing achieved by?

Answer 5

[ ] the square brackets

Question 6

What is the size function?

Answer 6

A class method for the std::array class, and returns the number of elements in the array.
- array.size()

Question 7

How do you make a variable const(read only)?

Answer 7

To make a variable const (read only) we use the const keyword in front of the variable type. Once a variable has been set as const, its value cannot be changed.

Question 8

What are the two main uses of const?

Answer 8

Preventing errors

• Stops you trying to change values that should stay the same
• Can make code more readable

Question 9

How else can you define constant values?

Answer 9

with the define keyword

- The general form of a define is: #define SYMBOL value

Question 10

What is an enum?

Answer 10

An enum is shorting for enumeration and

allows a series of constant symbols to be defined in a series, whereby each enums value is +1 of the previous value.

Question 11

Give an example of an enum.

Answer 11

enum waveTypes {
eSine = 0;
eSquare,
eSaw,
eReverseSaw,
eTri,
eNoise,
};