Unfortunately I am forced to use this book because of school. It’s very bad. It has a ton of errors in it, is outdated and the reinforcement exercises don't add up to the content taught in the book. Also, lots of things are shown that php doesn't usually get used for nowadays. At least I am learning that much.
How can I build a shopping cart when they don't go over anything to do with a shopping cart in the chapter? All text arrays when I need to use mathematics.
It doesn't make any sense and is pointless. Find another book.