3.1.1.10 Subroutines (procedures/functions)

Question 1

Define a subroutine.

Answer 1

A subroutine is a block of code which only runs when it is called.

Question 2

How is data passed in subroutines?

Answer 2

You can pass data, known as parameters, into a method.

Question 3

Define a procedure.

Answer 3

A subroutine that performs a specific task. When the task is complete, the subroutine ends and the main program continues where it left off.

Question 4

What are the two types of subroutines?

Answer 4

• Procedures.

- Functions.

Question 5

Outline the advantages of subroutines.

Answer 5

• Making programs shorter, easier to read and understand through breaking down program code into smaller sections.
• You can test procedures or functions separately rather than having to test the whole program, making programs easier to debug.
• If something needs to be changed in a subroutine, it only needs to be changed once, within the subroutine code. This change will then take effect wherever in the program the subroutine is used.

Question 6

Define a function.

Answer 6

A function works in the same way a procedure does, except it manipulates data and returns a result back from the main program.

Question 7

Define the syntax for running a subroutine.

Answer 7

E.g. a subroutine named ‘mySubroutine’.

Syntax:

mySubroutine( );

Question 8

Outline the uses of subroutines.

Answer 8

To reuse code: define the code once and use it many times.