Swift Test - Answers

The answers for a fun test on Swift I made for the iCapps Team Meeting on 2/7/2014.

Transcript

1. Swift Test! The answers…
2. Which of these statements won't compile? 1. if  (beers  >  0)  consumeBeer()   2. if  beers  >  0  {  consumeBeer()  }   3. if  (beers  >  0)  {  consumeBeer()  } 1
3. How would you declare a variable named awesome of type Double in Swift? 1. Double  awesome   2. var:double  awesome   3. var  awesome:Double 2
4. Which of these is not valid Swift? 1. class  iCapps  {}   2. enum  iCapps  {}   3. tuple  iCapps  {}   4. struct  iCapps  {} 3
5. Given: ! what is the result of: 1. stringValue  ==  nil   2. stringValue  ==  “Justin  Gif”   3. the  compiler  wont  allow  it 4 var  stringValue:String  =  “Justin  Gif”   stringValue  =  nil  
6. Given Objective-C: ! How would the Swift equivalent look? 1. rootController?.view?.label?.text  =  “OHAI”   2. rootController.view.label.text  =  “OHAI”   3. if  rootController  !=  nil  {       if  rootController.view  !=  nil  {         if  rootController.view.label  !=  nil  {           rootController.view.label.text  =  “OHAI”         }       }     } 5 rootController.view.label.text  =  @“OHAI”  
7. How do you declare class methods on a Swift class? 1. class   2. static   3. both 6
8. What is the mutating keyword for? 1. Indicates  a  class  can  mutate  its  properties   2. Indicates  a  method  on  a  struct  changes  the  struct’s   values   3. Indicates  that  a  variable  will  change  during  its   lifetime 7
9. Which of these is not a built in swift type? 1. Boolean   2. Int   3. String 8
10. What is the equivalent of Objective-C’s dealloc in Swift? 1. dealloc   2. dispose   3. deinit 9
11. What is the expected result? 1. a  =  [  33,  44  ]       b  =  [  33,  55  ]     2. a  =  [  33,  55  ]       b  =  [  33,  55  ]   3. compiler  will  not  allow  it 10 let  a  =  [  33,  44  ]   let  b  =  a   b[1]  =  55  
12. What is the expected result? 1. a  =  [  33,  44  ]       b  =  [  33,  44,  55  ]     2. a  =  [  33,  44,  55  ]       b  =  [  33,  44,  55  ]   3. compiler  will  not  allow  it 11 let  a  =  [  33,  44  ]   let  b  =  a   b.append(55)  
13. How do you declare an IBOutlet property? 1. @IBOutlet  var  button:UIButton   2. var  button:UIButton(IBOutlet)   3. var  button:UIButton<outlet> 12
14. let  firstString:String?  =  “abc”   let  secondString:String!  =  “abc”   Which of these lines will compile? 1. print  firstString?     print  secondString!   2. print  firstString!     print  secondString   3. print  firstString?     print  secondString   4. print  firstString     print  secondString 13