3. The programmer’s job can be broken down
into six programming steps:
1. Understand the problem
2. Plan the logic
3. Code the program
4. Translate the program into machine language
5. Test the program
6. Put the program into production
4. Programmers must first understand what it is
the user wants
To understand the problem, you must analyze it
Really understanding the problem may be one of
the most difficult aspects of programming
The description of what the user needs may be vague
The user may not even really know what he or she
wants
Users who think they know what they want frequently
change their minds after seeing sample output
5. Programmer plans the steps to the
program, deciding what steps to include and
how to order them
Example
Planning tour
Planning party
The two most common tools
flowcharts : pictorial representation
Pseudocode : English-like representation
6. start
Flowcharts
A pictorial representation of get
the logical steps it takes to InputNumber
solve a problem.
Uses Standardized Symbols calculatedAnswer =
InputNumber * 2
Utilize Formula Notation
Typically Read from Top to print
Bottom or from Left to Right on calculatedAnswer
a Page
stop
7. Pseudocode
An English-like representation of the logical steps
it takes to solve a problem
pseudo – a prefix that means false
Short English-Like Statements
Not Standardized
Proper use of indentation
Example start
get InputNumber
compute calculatedAnswer as InputNumber times 2
print calculatedAnswer
stop
8. Writing the program in one of more than 400
programming languages
Pascal, Assembly Language, C, C++, Java…..
Concentrate on the syntax of the language
Exact instruction, symbol, …. ?
Some very experienced programmers
successfully combining the logic planning and the
actual instruction writing, or coding of the program, in
one step
Writing a cinema scenario
9. Objective
Each computer knows only one language, Machine
Language.
High-level Languages must be translated into Machine
Language
Need to compiler or interpreter
Compiler catches every syntax error.
When writing a program, a programmer might need to
recompile the code several times
An executable program is created only when the code
is free of syntax errors
10. Why does it need to be tested ?
Syntax Errors : by compile
Logical Errors : by test
Test
Executing the program with some sample data
Seeing whether or not the results are logically correct.
being tested with many sets of data carefully
Example Logically incorrect
start
get InputNumber
compute calculatedAnswer as InputNumber times 20
print calculatedAnswer
stop
11. Once the program is tested adequately, it is
ready for the organization to use.
Putting the program into production might
mean simply running the program once if it
was written to satisfy a user’s request for a
special list.
12.
13. By wikipedia definition:
“A flowchart is a schematic representation
of an algorithm or a stepwise process,
showing the steps as boxes of various kinds,
and their order by connecting these with
arrows.”
“Flowcharts are used in designing or
documenting a process or program.”
14. Start/Stop Process Input/Output
(Terminator) (Rectangle) (Parallelogram)
Decision Connector Flowlines Predefined Process
(Diamond) (Circle) (Arrows) (Rectangle)
15. Input/Output
Generalised Input/Output
Block; reading data from an
input medium or writing data to
an output medium. This block Input/Output
(Parallelogram)
should be used in situation were
data is being sent in and out of
the processor via some sort of
I/O peripheral.
16. Process
Any process step; an
operation or group of
operations that cause a
change in value, form or Process
location of the data. This (Rectangle)
can consist of arithmetic
or logical operators or
even move commands.
17. Flow line
Sequence of operations
and direction of data flow;
arrowheads are required if
linkage is not left-to-right Flowlines
or top-to-bottom. (Arrows)
Generally arrowheads are
included to avoid
confusion.
18. Annotation
Additional explanation or
comments. This block is
used for providing
additional information to
any other block in the
flowchart.
19. Decision
Decision-making or
switching type of
operation, usually based on
a comparison, that
Decision
determines which of a (Diamond)
number of paths should be
followed.
20. Predefined Process
One or more operation
defined in more detail
elsewhere, such as in a
booklet or on a different
flowchart, but not on Predefined Process
(Rectangle)
another part of the
flowchart in which this
symbol appears.
21. Terminal
Terminal point in a
flowchart – stop, start or
break in the line of flow.
Start/Stop
(Terminator)
22. Connectors
Entry to or exit from
another part of the
flowchart; if to or from step
is on another page then the
page reference should also
be stated. Connector
(Circle)
23.
24.
25. Use a standardized flowcharting template,
with clearly recognizable symbols. Follow ANSI
recommendations for symbol use.
Do not crowd or clutter the flowchart, ensure
proper spacing between symbols.
Number the pages of your flowchart
sequentially. Specifically the title of program,
the date and the author on each separate
page.
26. Chart the main line of data flow in the system
or program first, then incorporate detail in later
flowchart.
Write within symbols avoid using too many
words. If necessary use the annotation symbol.
Choose wording to suit the anticipated readers
of the flowchart.
27. Be legible, neatness counts.
If flowchart becomes complex use connector
symbols to reduce the number of flow lines.
Collect incoming and outgoing flow lines so
that the number of lines entering or leaving a
symbol are minimized.
28. Use the flowchart as a guide when coding;
change it when necessary to ensure the
flowchart reflects the steps implemented in the
code.
Cross-reference portion of the flowchart to the
source language code.
Be consistent with the level of detail shown in
the flowchart. Do not chart every detail, but do
not leave out important details.
29. Put yourself in the position of the reader; try to
anticipate the reader’s problems in
understanding the flowchart.
31. entrance
The SEQUENCE process is
just a series of processes
carried out one after the
another.
Most programs are
represented at the highest
level by the sequence ,
possible with a loop from
exit
end back to the beginning.
32. The If-THEN-ELSE process entrance
logically completes the
binary decision block by
providing two separate
processes.
One of the processes will be
carried out in the each path
from the binary decision.
This is also called
exit
SELECTION.
33. The WHILE process is allow
entrance
for the representation of a
conditional loop structure
within a program.
The decision to execute the
process is the loop is made
prior to the execution of the
process.
exit
This is also called
REPETITION.