*

1 files changed, 15 insertions, 1 deletions

diff --git a/notes.txt b/notes.txt
index 3f3909a..432e430 100644
--- a/notes.txt
+++ b/notes.txt
@@ -3,4 +3,18 @@
 - Arithmetic operations are constant 
 - Variable assignment is constant 
 - Accessing element in an array (by index) or object (by key) is constant
-- In a loop, the complexity is the length of the loop times the complexity of whatever happens inside of the loop
\ No newline at end of file
+- In a loop, the complexity is the length of the loop times the complexity of whatever happens inside of the loop
+
+# SOLID
+
+- Single responsibility principle
+	- a class should only have 1 reason to change
+	- *separation of concerns* -- different classes handling different, independent tasks/problems 
+- Open-closed principle
+	- classes should be open for extension but closed for modification
+- Liskove substitution principle 
+	- you should be able to substitute a base type of a subtype
+- Interface segregation principle 
+	- don't put too much into an interface; split into seperate interfaces 
+- Dependency inversion principle 
+	- high-level modules should no depend on low-level ones; use abstraction
\ No newline at end of file