/iOS-Week4-Swift-Assessment-ios-0616

Primary LanguageSwift

iOS Week 4 Swift Assessment

This assessment is designed to test students' ability to create view controllers, navigation controllers, and nested views in Interface Builder, then combine these elements programmatically.

The resulting program should display a list of words in a table view which shift in position when a "Shift" button is tapped.

Part 1

You are provided two files: Main.storyboard and ViewController.swift.

Storyboard

  • In Interface Builder, add a view controller.
  • Embed that view controller inside a navigation controller.
  • Set the custom class of the view controller in Interface Builder to the ViewController.swift file.
  • In Interface Builder, add a table view to the view of the view controller.
  • Add a prototype cell to the table view and set its reuse identifier to basicCell.
  • Create an IBOutlet from this table view to the ViewController.swift file and name this outlet tableView.

ViewController Class

  • Start by typing the following at the end of the viewDidLoad() method.
tableView.delegate = self
tableView.dataSource = self

  • These lines indicate the view controller has adopted the UITableViewDataSource and UITableViewDelegate protocols. Since this view controller is claiming to take on the responsibility for table views, what functions do we need to implement? Don't implement those functions (yet), but declare them to get rid of the visible errors.

  • We want to be able to store Strings inside of an Array within our ViewController that will ultimately be displayed inside our tableView. Add an instance property on ViewController called electricWords. Its default value should be an array of words. What words? Each word from this sentence:

We're going to rock down to Electric Avenue

  • We need to set up the constraints on our tableView, but not in Interface Builder. You're going to set up constraints in code! Create a separate function called setupTableView() that takes in no arguments and returns nothing. The sole purpose of this function is to setup the proper constraints as follows:

    • tableView width should equal the width of the view
    • tableView height should be 75% of the height of the view
    • tableView center X should be equal to the view's center X.
    • tableView bottom should equal the view's bottom.

  • Implement those table view methods you were asked to declare above. What content is being displayed? How many rows do we need? How do we create a cell to populate each row?

Run the app and see that each row in your table view contains one word from the provided sentence.

Part 2

  • Create a function called shift(number:words:), which takes in an Int and an Array of Strings and returns an Array of Strings. This function should shift the contents of the Array argument by the number of spaces indicated by the Int argument. The shifted array is what should be returned. For example:
let billWords = ["Bill", "Nye", "the", "Science", "Guy"]

print(billWords)
// prints "["Bill", "Nye", "the", "Science", "Guy"]"

let result = shift(number: 2, words: billWords)

print(result)
// prints "["Science", "Guy", "Bill", "Nye", "the"]"
  • In Interface Builder add a bar button item to the navigation bar and change its text to Shift.
  • Connect this button to an IBAction called shiftButtonTapped in the ViewController class.
  • The following should happen when the Shift button is tapped:
    • A random number should be generated.
    • The shift function should be called and the random number and electricWords should be passed in as arguments. The return should be assigned to electricWords.
    • tableView should be updated with the shifted array's contents.

Run the app and see that tapping the Shift button results in the strings shifting appropriately.