The dollar is not a prefix, it seems to be a generated code for property wrapper, and each kind of property wrapper can determine which value it return via this dollar sign
State and ObservedObject are popular property wrappers in SwiftUI
State
Read State
A persistent value of a given type, through which a view reads and monitors the value.
If we have a simple State, we can access its 3 forms
@State private var image…

