100 days of swiftUI

Day 10: class
I learnt: deinit, private, different behavior of struct/class; uikit most of view are ass, data are struct; swoftUi the opposite
Additional reading: how struct implement mutating -> an inout behavior for self; all mutating in struct is create a new value, the behavior is optimized with copy on write

Day 11: protocol
What I learnt: protocol inheritance, protocol extension , protocol oriented programming
What I’m not quite understand: adding mutating keyword at protocol function or getting cannot use mutating number on immutable value: self is immutable error
Solution:
Implement a non- mutating version: (mutating keyword implicitly makes the instance itself - self- an inout parameter, and pass it as a first argument into the methods parameter list.
Enforce class only for the protocol
Use struct to

Day 12: optionals
Unwrapping, nil coalescing, implicit unwrap, optional chaining , failable initializers, type casting
Reading: optional protocol( objec annotations)

Day 13: review part 1
Review data type/functions/dict/switch syntax etc

Day 14: review part 2
Options/ struct/ class recap

Day 15: properties/get set compute property,polymorphism/cal/ type casting/
Reading: at protocol extension, if use self- current value but use Self means the current data type

Day 16: we split app overview: form/navigation view/@state

Day 17: form,syntax to use @state property(with$), picker, foreach

Day 18:
Wesplit wrap up
No more than 10 child views inside group, %f, %g meaning format
Body property is compute property in swiftUIview  
Picker/segment picker style
From can scroll
Two way binding with$
Navigation Bar title should be modifying the view inside navigation view instead of navigation view itself
For each views loop over 10 items of view
Text field always bind to strings

Day 19: challenge day - write a simple metric conversion app: temperature