1. BPC.1 Basic Programming Concepts
1.1 Program development procedures
1.2 Problem analysis techniques
1.3 Algorithm design
1.4 Program debugging
1.5 Program documentation
1.6 Problem solving approaches
1.7 Structured programming
1.8 Good programming style

2. Program development procedures

3. Program development procedures

4. Problem Analysis Concept of modularity Stepwise refinement
Divide the statements into logical groups called module.
Each module performs one or two tasks.
The modules are usually written in the form of sub-programs.
Stepwise refinement
Break down a problem into smaller parts (or modules) until it becomes manageable.

5. Designing an algorithm
a set of ordered steps
Pseudocode is used to shorten the statement
There is NO syntax in writing algorithm
Pseudocode may include basic programming:
1. Using assignment statement
e.g. A5, A = 5 or A := 5 means putting 5 into variable A
2. Using conditional statements, like
If...then...else...end if, represent different actions some conditions.
3. Using indentation to clarify the statements blocks.

6. Using program flowchart to realise algorithm
Graphical representation of instructions
Representing the logic of a single program
Can be converted into programming constructs:
branching
iteration structures

7. E.g. 1
Example 1 Assign different value to Y depending on the input value.

8. E.g. 2
Example 2 Calculate the sum of
Output is 55

9. Debugging and Testing Debugging Testing
Finding out errors (bugs錯誤[蟲]) and
Removing them
Compare the output with the expected one
Testing
Verify that the program will process all data properly
Should use both
valid and invalid test data

10. Programming Errors 1. Syntax (語法) Errors 2. Run-time (執行) Errors
Violation of the grammatical rule of a programming language
e.g. Wrong spelling of some keywords
2. Run-time (執行) Errors
Cause a program to terminate abnormally
e.g. Division-by-zero error, Out of memory error.
3. Logical (邏輯) Errors
Caused by an incorrect algorithm
Producing an unexpected result, e.g. an average mark > 100
May not be discovered until it is too late
So, programs should be well tested before use

11. Documentation Documentation User manual
Written description about the solution to a problem
User manual
Instruct user how to operate the program effectively
Including:
1. Procedures in starting the program
2. Description of buttons/commands in the menu
3. Description of error messages and how to handle such errors
4. Description of defaults values
5. Sample procedures in finishing a task

12. Documentation Technical documentation
for programmers or technical people
providing information about how the solution is developed
Useful for maintenance and further development
Including:
1. Description of the problem
2. Algorithm
3. Program flowchart
4. Program listing with comments
5. List of files used
6. Test data
7. Sample output

13. Different Ways to Solve a Problem
A. Packaged software vs Custom software
Packaged software
Pre-written software available for purchase
Less expensive
Company may need to adjust in order to use packaged software
Custom software
Written by IT department
Match the company’s requirements
But, more expensive and take a longer time to develop

14. Different Ways to Solve a Problem
B. Planning vs Without Planning
Usually more than one logical solution
An easy one may solve the problem temporarily
But, when new problem arises, programs may be difficult to change
Programs should have careful planning before development
Otherwise, take much longer and more effort to change

15. Structured programming
Sequence
Steps follow each other in a logical sequence.
Alternation
They may be if or case statements.
Iteration
They are while, for or repeat statements.

16. Good programming style
Structured program
Modular design
Readable
Reusable
Reliable
Portable
Program documentation