Swift 3 :– Iterating through Dictionaries & Logical AND OR operators

Iterating through Dictionaries

//create a Swift 3 dictionary with values

// just to show we can, lets change the value types, 

// so the dictionary type is [String : AnyObject]

var someDict = ["Current Zip Code" : 34050, "Previous Zip Code" : 43256, "Next Zip" : "the moon"]

var someString:String = "" // will use later...

for (theKey, theValue) in someDict {

    //iterate through the dictionary until we find the previous zip code

    if (theKey == "Previous Zip Code") {

        //check what the value type is before doing anything with it

        if let possibleNumber:Int  = theValue as? Int {

            //possibleNumber was successfully created equaling theValue

           print (possibleNumber)

        }

    }

    // another approach... 

    else if (theKey == "Next Zip") {

        //check if its a string...

        if (theValue is String) {

            //it's safe to force someString to equal theValue since

            // we know it's definitely a string...

            someString = theValue as! String

        }

    }

}

Logical AND OR operators

//set up a bunch of conditional variables to test in our if statement that contains AND plus OR operators.

let hasDoorKey = false

let knowsOverridePassword = true

let enteredDoorCode = false

let passedRetinaScan = true

// && is an AND operators and checks if BOTH conditions are true

// || is an OR operator, so only one OR condition needs to be true to proceed

if ((enteredDoorCode && passedRetinaScan) || hasDoorKey || knowsOverridePassword) {

    //the first condition was false because only one was true (passedRetinaScan)

    // the second condition (hasDoorKey) also false

    // the third condition knowsOverridePassword was true though

    print ("Welcome")    

} else {

    print ( "DENIED")

}

reference :- http://swift3tutorials.com/