This challenge allows you to put some of the lessons you learned today into practice in a simple iOS application.

Create a new iOS single view application and clean it up according to your preferences.

Build a new Student.swift file based on the following type and conform it to both CustomStringConvertable and Codable. Make sure to implement a custom description property that describes your student in a string.

struct Student: CustomStringConvertible, Codable {
  let name: String
  let age: Int?
  let cohort: String?
}

Create a StudentManager.swift file. Your StudentManager type should be a class, descended from NSObject. It will store an array of students in a variable property called students.

Add the following skeleton for writing to and reading from your device's file system:

let url = URL(fileURLWithPath: NSHomeDirectory())
    .appendingPathComponent("Documents")
    .appendingPathComponent("students.json")
    
func writeToFile() {
}    

func readFromFile() {
}

You can write data to a file url with data.write(to: url) and read it with Data(contentsOf: url). Both of these calls will throw so you'll need to use do-catch. Further, you can't just write or read an array of Student. You need to encode to JSON data before writing and decode after reading.

Implement these methods for your StudentManager type.

Create an interface that allows you to add one student at a time. Remember, every student must have a name but the student's age and cohort are optional. Add three labels (name, age, cohort) and three fields as well as a Save button that calls the StudentManager's writeToFile(). You'll want to create a StudentManager object and connect it to your primary view controller.

Add and implement a print button that prints a list of the students to the console.

Finally, add a view controller viewWillAppear method that calls readFromFile so your stored data can be printed even after you quit and restart the application.