Design Techniques

During the course we will discuss the following types of notations, these may be used across a variety of problems.

Pseudocode is a textual design notation. It is written in a mix of code and english but is not written in any specific programming language. It used by the programmer to help design the main steps of their program.

• One line of pseudocode should be equivalent to roughly one line of code.

The main steps are numbered as 1,2,3. And these steps can be refined (expanded) into smaller steps - 1.1, 2.1, 3.1 etc

1 Inputs:

1.1 User inputs the Pupil Name

1.2 User inputs the Prelim Mark 

1.3 User inputs the Assignment Mark

2 Processes

2.1 percentage = (prelim mark + assignment mark/160)

2.2 percentage = percentage rounded to 2 decimal places

3 Output

3.1 For every pupil

3.2 Display the name of a pupil with their prelim and coursework mark

3.2 Display the pupil's percentage

3.3 Next pupil

Variables are assigned and updated using the following assignment statement:

SET variablename TO value

Examples:

counter TO counter + 1

answer = length * breadth

To receive or send a value from keyboard:

username = Input from user

age = Input from user

Display passmark

Conditional commands have the form:

IF expression THEN command END IF 

or  

IF expression THEN command ELSE command END IF

Examples:

IF a > 3 

   Display “more than three” 

END IF

IF mark > 70 

   Display “You gained a merit!”

ELSE IF mark > 50 

   Display “Well done you have passed”

ELSE

   Display “Sorry you have not passed”

END IF

Repetition occurs when either a fixed or conditional loop is being used.

Example

FOR counter FROM 1 TO 5 DO 

    Display counter

END FOR