for loop print json array

var dicArray = [

    ["quote": "Some text here1", "author": "guy1"],

    ["quote": "Some text here2", "author": "guy2"]

]

for element in dicArray {

    print(element)

    for(key,val) in element{

        print("key: \(key) /  val: \(val)")

    }

}

leancloud query, call back , get value

        let query: AVQuery = AVQuery(className: "story")

        query.whereKey("objectId", equalTo: "56c6f8362e958a0059fcd854")

        query.includeKey("question")

        

        

        query.findObjectsInBackgroundWithBlock({(objects: [AnyObject]?, error: NSError?) in

            

            let obj: AVObject = objects![0] as! AVObject

            let q: AVObject = obj["question"] as! AVObject

            

            self.studentLabel?.text = String(obj["name"])

            self.idLabel?.text = String(obj["object"])

            self.questionLabel?.text = String(q["name"])        

        })

EXC_BAD_INSTRUCTION (code=EXC_1386_INVOP, subcode=0x0)

when assigning a null val
or dividing a 0

@IBOutlet, Interface Builder scans

prefixing these variables with the @IBOutlet keyword. Interface Builder scans your code looking for any properties in your view controller prefixed with this keyword.

! , exclamation mark , implicitly unwrapped

exclamation mark (!). This indicates the variables are optional values, but they are implicitly unwrapped. 

Auto Layout

third button in the lower right of the Interface Builder (which looks like a Tie Fighter) and select All Views\Add Missing Constraints.

swift function declare

Functions with Parameters




Functions Without Return Values


Functions with Optional Return Types


Variadic Parameters
 to define function with multiple number of arguments


Pass by Reference 

protocal

 - A protocol defines a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality.

 - The protocol can then be adopted by a class, structure, or enumeration to provide an actual implementation of those requirements.

value of optional type not unwrapped did you mean to use '! ' or '?'

value of optional type not unwrapped did you mean to use '! ' or '?'