Variable Types

Question 1

what are the five types of variables?

Answer 1

Constants, global variables, class variables, instance variables, and local variables

Question 2

how is a constant variable declared?

When is it used?

Answer 2

by capitalizing every letter in the variable’s name
MY_CONSTANT = ‘I am available throughout your app.’

used for storing data that never needs to change.

Question 3

Can Constants be declared in method definitions?

Answer 3

no

Question 4

how are Global variables defined?

Answer 4

declared by starting the variable name with the dollar sign ($).

$var = ‘I am also available throughout your app.’

Question 5

why are defining Global variables dangerous?

Answer 5

These variables are available throughout your entire app, overriding all scope boundaries.

Question 6

How are Class variables declared?

Answer 6

starting the variable name with two @ signs

@@instances = 0

Question 7

How are Class variables accessed?

Answer 7

accessible by instances of your class, as well as the class itself.

Question 8

List an example of when you should use a class variable

Answer 8

When you need to declare a variable that is related to a class, but each instance of that class does not need its own value for this variable

Question 9

how is a class variable initialized?

Answer 9

initialized at the class level, outside of any method definitions.

Question 10

how can class variables be altered?

Answer 10

altered using class or instance method definitions.

Question 11

how are Instance variables declared?

Answer 11

starting the variable name with one @ sign.

@var = ‘I am available throughout the current instance of this class.’