25. Likov substitution principle
objects in a program should
be replaceable with
instances of their subtypes
without altering the
correctness of that program
27. Dependency inversion principle
one should “Depend upon
Abstractions. Do not depend
upon concretions.” Dependency
injection is one method of
following this principle.
28. オブジェクト健康体操
●
One level of indentation per method
●
Don't use the ELSE keyword
●
Wrap all primitives and Strings
●
First class collections
●
One dot per line
●
Don't abbreviate
●
Keep all entities small
●
No classes with more than two instance variables
●
No getters/setters/properties
29. Pair Programming Ping Pong Pattern
●
A writes a new test and sees that it fails.
●
B implements the code needed to pass the
test.
●
B writes the next test and sees that it fails.
●
A implements the code needed to pass the
test.