WWDC 2015: The Pregame Quiz

// Written by Jordan Morgan // Jun 5th, 2015 // Read it in about 1 minutes // RE: Trivia

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Among my favorite entries to the always insightful NSHipster posts are the annual trivia questions.

They’ve always been put together in a way that challenges the most embattled iOS developers among us, yet they give the newly minted Cocoa Touch programmer a fighting chance.

As a tribute to those fond memories I have of participating in them, this week I’ll take a different approach and instead create one of my own.

Challengers — start your runloops.

Ground Rules

There are three rounds, and the point break down is as follows:

• Round 1 –1 point each answer
• Round 2 - 2 points each answer
• Round 3 - 3 points each answer

The last question of each round is an optional wildcard question. Get it right, and your team gets 4 points, but miss it and the team will be deducted 2 points.

As with the NSHipster quiz, it’s best to write down each answer on paper and then present them. Because, you know, cheating.

Ready?

Round 1 — Swift Softball Questions

Question 1:
The environment to quickly debug and prototype Swift code that supports markdown and near instant execution that was announced at WWDC 14 is called what?

Question 2:
In order to expose Objective-C code to Swift, one must add what to their project?

Question 3:
Swift requires the use of parenthesis around if statements, true of false?

Question 4:
How many access level modifiers does Swift have?

Wildcard:
Swift’s logo contains a bird, which is specifically called a __?

Round 2 — Bring Your Thinking Cap

Question 1:
Instead of calling methods, Objective-C’s model of Object Oriented Programming revolves around what technique?

Question 2:
Swift ensures each variable will be initialized by using definitive initialization by specifically using which part of the compiler?
a) Front end
b) Optimizer
c) Back end
d) None of these

Question 3:
To create a variable in Swift that uses unmanaged memory, one uses which type specifier?

Question 4:
What controversial technique is used by the Foundation Framework to implement Key-Value Observing?

Wildcard:
The author of Swift’s compiler is who?

Round 3 — Senior Developers Only

Question 1:
Given a valid Swift class, a variable of type Int? will bridge to what in Objective-C code?

Question 2:
In Swift, a weakly referenced variable can be declared as a constant: True or false?

Question 3 (code challenge):
Overload the “+” operator to return a string _x _numbers of times that’s comma delimited. Ex: “Hi” + 3 //Hi, Hi, Hi

Question 4:
Aside form AnyObject, there is one protocol that is returned as a type in the Swift standard library. What is it?

Wildcard:
Finish the sentence. At WWDC 14, it was famously declared that Swift is “Objective-C __ ___ __!”

Answer Key

Round 1:

1. Playgrounds
2. A bridging header file
3. False
4. 3 — public, internal, and private.
5. Wildcard: A swift — gotcha.

Round 2:

1. Message Passing
2. B — Optimizer
3. UnsafePointer
4. Method Swizzling
5. Wildcard: Chris Lattner

Round 3:

1. It won’t, Swift’s optional value types are not bridged over to Objective-C.
2. False — Weak references must be declared as variables, to indicate that their value can change at runtime. A weak reference cannot be declared as a constant.
3. Code passes as long as it overloads the “+” operator and returns the expected result. Here is a sample that accomplishes this:

   func + (word:String, iterations:Int) -> String
   {
    var result:String = word
    for _ in 1..<iterations
    {
        result += “, “ + word
    }
      
    return result
   }
   //"Hi, Hi, Hi, Hi"
   print(“Yo” + 4)
   

4. MirrorType — Used for reflection.
5. Wildcard: “Objective-C without the C.”