We learned about Design Patterns

□Flexible
change something that already exists
Desktop > Laptop

□Extensible
ability that adding one thing to current system
→Desktop
We can extend parts easily. For example, keyboard, software, screen, etc

□Destractors of Flexibility
- complex and uncreadable code
・bag name
　ex) char * c ×
　 　　char * contact ○
We don't understand that what 'c' does mean.

- violation of single responsibility principle
ex) Fan has only the function of fan. So it should not have the function of
lighgt because it becomes complex in case of repair.
So one thing has one functionh.

- Repetition　

example is below↓

Student class has the function of "sort()" and cource class also has the function of "sort()".

So to avoid repetion of "sort()", we make sorter class that has the function of "sort()". Then if we use the function of sort(), we refer sort from sorter class.

do not have to write sort() at student class and cource class.

□Design Decisions For Flexibility
- DRY
Do notrepeat yourself

- keep it simple

- loose coupling
・not tight nonnection
Car and Wheel are loosely coupled
Desktop is loosely coupled
Laptop is not loosely coupled

example is below↓

f1(sedan c){
c.turn();
}

f2(sports car c){
c.turn();
}

↓

f1(car c){
c.turn();
}

We can use "turn()" both at sprts car and sedan.
⇒Polymorphism

- separating thing that change
if we mix curry and rice, we cannot remove each thing.

□activity diagrams

–step what we are doing something

–similar to flow chart

□state machine diagram

–shows us change of state of one object as the object gets event come from outside

□sequence diagram

–which object are going to interact each other while these steps are happening

□difference between sequence and activity diagrams

–sequence → has time sequence, sunny day scenario(everything is perfect)

–activity → has decision

high level overview of the steps

I learned about the detailes of UML

UML

=(Booch+OMT)+OOSE

=managed by the OMG

=has own symbols(rules)

□UML diagrams

=structural diagrams

->how module(function) connect each other

=behavioral diagrams

->how will module behavior

ex) refresh press

->what happen inside?

=interaction diagrams

→three high level categories of diagram

□UML structural diagrams

–class diagram ->has connection, identify between the classes

–object diagram ->what class our system contain

–component diagram ->grouping

–composite structure diagram

–package diagram

–deployment diagram

□class

class has name, attributes and behavior

□UML behavior diagram

–use case diagram

–activity diagram (similar to flow chart)

–state machine diagram

□UML interaction diagrams

–sequence diagrams

–communication diagrams

–interaction overview diagrams

□use case

- one thing you can do with the system

What I learned today

・UML
→NOTATION(COMMON LANGUAGE)

・Why do we need Drawing(planning)?
→We do not want to do mistake

・stake holders
→Archtect, construction, company, buyers

・high level design
→real
all stake holders can understand

・What-if?
→what-if the wheel was not round?
→to avoid miss

・re-use
→use design that the best many time
If we design one door, we can re-use 10 building

・module
→keyboard, screen, mouse, touchpad, etc

・Benefits of Modeling
- communication
- risk reduction
- high level design
- what-if analysis
- re-using components