1. CHAPTER 2 & 3: Pseudocode and Developing and Algorithm

2. Objectives Introduce common words & meaningful names
Define basic control structures in Structure Theorem
Develop an algorithm

3. Computer Operations Receive information Output information
Perform Arithmetic
Assign a value
Compare variables
Repeat actions

4. Receive information Read and Get
Read: receive input from a record on a file
Get: receive input from keyboard
Example:
Read studentName
Get systemDate

5. Output Information Print, Write, Put, Output, Display Examples:
Print: output to printer
Write: written to a file
Put, Output or Display: output to screen
Examples:
Write customer name to master file
Display ‘Total Number’

6. Arithmetic Add, Subtract, Multiply, Compute etc Examples:
Add number to total
Total= Total + number
Compute C = (F-32)*5/9
Order of operations is very important

7. Assign a value 3 instances of assigning a value:
Initialize: Initialise or Set
Result of processing: ‘=‘ or ‘’
Store a value: Save or Store
Examples:
Initialise total_price to zero
total_price= cost_price + sales_tax

8. Compare
Compare 2 variables & select one of the two alternative actions.
IF, THEN, ELSE
Example:
IF student_status is part_time THEN
add 1 to part_time_count
ELSE
add 1 to full_time_count
ENDIF

9. Repeat actions Sequence of processing that need to be repeated
DOWHILE, ENDDO
Example:
DOWHILE student_count <5
Read Student record
Print student name, address to report
add 1 to student_total
ENDDO

10. Meaningful names Name should describe the type of data in the variable
More than one word, use:
Camel casing
Underscore

11. Structure Theorem
Any computer program can be written using 3 basic control structures:
Sequence
Selection
Repetition

12. Sequence Straightforward execution of one step after another Example:
Statement 1
Statement 2
Statement 3
Receive, output, arithmetic & assign values

13. Selection
Presentation of a condition and choice between 2 actions, depending on TRUE or FALSE
Example:
IF condition 1 is true THEN
statement(s) in true case
ELSE
statement(s) in false case
ENDIF

14. Repetition
Presentation of a set of instructions to be performed repeatedly as long as the condition is true.
Example:
DOWHILE condition 1 is true
statement block
ENDDO