Using programme to get to previous page

navigationController!.popViewController(animated: true)

Comments

Post a Comment

Popular posts from this blog

Swift Basics: Arrays

Collections and tuples Types of collections: Arrays, dictionaries, and sets. All items stored in collections have to be of the same type. Collections can be constant or variable. (Use let or var) Arrays Each item in an array is an element. We can initialise arrays like this: let firstArray = [1, 2, 3] We can also declare them like this (these arrays are empty at first): var secondArray = [Int]() var thirdArray: [Int] = [] We can create arrays to store String, Double, SelfCreatedObjects We can create arrays to store more than one type: var fourthArray: [Any] = [1, "Three"] We can also create arrays that can store objects of any class type: var fifthArray:[AnyObject] = [] We can initialise an array to have 5 elements, each having the number 1: var sixthArray = [Int](repeating: 1, count: 5) We can create 2 dimensional arrays: var twoD1 =[[1,2], [3,4],[5,6],[7,8]] var twoD2 = [[Int]]() To access the elements of an array: It starts with 0: print(firstArray[0]) //will print 1 To ac...
Read more

Swift 4 basics - protocols

Protocols: Something like interfaces, where we describe the methods, properties and requirements of a type without providing implementation. Here is how to define a protocol: protocol MyProtocol{  var a: Int{get set}  var b: String{get set}  var readOnlyVar: String{get}  //var a, b, and c will have to be listed as properties in any class implementing the protocol  func getBSquared() -> Int //this method will have to be defined and implemented in the class that implements this protocol } To implement it in a structure: struct MyStruct: MyProtocol{} A structure can implement more than one protocol: struct MyStruct: Proto1, Proto2, Proto3{} If a class both implements and inherits, we can define the class by inheriting first, then by implementing: Class MyClass: TheParentClass, Proto1, Proto2{} Protocols can be used as types var aProto = Proto1 Can be stored in arrays: var proto: [Proto1] = [] You however, cannot create an instance of a protocol. You can create a...
Read more

Swift Basics - Tuples

You can use tuples to group multiple values of different types into a single value. var food = ("Ice cream", 'Strawberry", 3, 150) You can give each a name: var (dish, flavour, scoops, calories) = food To get an item from the tuple: var dish = food.0 var flavour = food.1 You can also create a tuple with a key:name association: var food = (dish:"Ice cream", flavour:"Strawberry", scoop:3, calories:150.2) You can use tuples in place of classes and objects that do not have any methods.
Read more