Files created with textbooks to get up to speed on Swift development.
Mastering Swift 5 has completely been uploaded, each chapter has a corresponding PlayGrounds file that goes occordingly with the respective chapter. Not everything is written in the comments from the chapters but what I believed to be important was written as comments and then shown with an example.
Pro Swift 4.1 Edition
Swift Protocol-Oriented Programming
iOS 13 Programming Fundamentals with Swift