4.1 Fundamentals of Programming

Question 1

What is the difference between a variable and a constant?

Answer 1

A variable has a value that can be changed during execution, a constant’s value stays the same.

Question 2

What are advantages of using named constants in programming?

Answer 2

Avoid repetition of important values.

Easier to remember the constant name than its value.

Question 3

What is a subroutine?

Answer 3

A named ‘out of line’ block of code that may be executed by writing its name in the program

Question 4

What are advantages of using subroutines in programs?

Answer 4

Decomposes the program into several parts making it easier to solve problems.
Easier to debug.
Easier to understand the code.

Question 5

What is the scope of a local variable?

Answer 5

Within its subroutine.

Question 6

When does a local variable exist?

Answer 6

Only when the subroutine it is in is running.

Question 7

Why is it good practise to use local variables (instead of global ones)

Answer 7

Local variables only take up memory space whilst their subroutine is run.

Question 8

Describe a class

Answer 8

Something that defines methods and properties which capture the behaviour and common characteristics of objects.