CustomStringConvertible in Swift



  • Apple says: "A type with a customized textual representation. Types that conform to the CustomStringConvertible protocol can provide their own representation to be used when converting an instance to a string. The String(describing:) initializer is the preferred way to convert an instance of any type to a string"
  • CustomStringConvertible is a protocol and it's used print informative data of your object.



Ok So let's start

class Employee{
    let name: String
    let surname: String
    
    init(name: String, surname: String) {
        self.name = name
        self.surname = surname
    }
}

let emp = Employee(name: "Pawan", surname: "Manjani")
print(emp)

  • So here if you print your class instance then it will print like below

<YourProjectName.Employee: 0x60000152b240>

  • So what we see here is not very informative, So if you want to print a readable data over here so here CustomStringConvertible will help you.



class Employee: CustomStringConvertible { 
    let name: String
    let surname: String
    
    init(name: String, surname: String) {
        self.name = name
        self.surname = surname
    }
}

//Now let's conform to CustomStringConvertible Protocol
extension Employee: CustomStringConvertible { 
    var description: String { //by implementing description property (var)
        return "My name is \(name) + " " + \(serial)"
    }
}

let emp = Employee(name: "Pawan", surname: "Manjani")
print(emp)

  • So now if you print your class instance then it will print like below
"My name is Pawan Manjani"


Can we use CustomStringConvertible with struct??

YES 😎

 Thanks for reading, Happy Coding 💻

Popular posts from this blog

Frame vs bounds in Swift

Image
1 ,  Frame The  frame  of an  UIView  is the  rectangle , expressed as a location (x,y) and size (width, height) relative to the superview it is contained within. In short ,  a view's location and size using the  parent view's coordinate system 2 ,  Bounds The  bounds  of an  UIView  is the  rectangle , expressed as a location (x,y) and size (width, height) relative to its own coordinate system (0,0).   In short ,  a view's location and size using  its own coordinate system Example: Frame origin = ( 40 , 60 ) width = 80 height = 130 Bounds origin = ( 0 , 0 ) width = 80 height = 130 Thanks for reading, Happy Coding  👨‍💻  
Continue Reading »

Property wrapper in Swift

Image
Property wrapper is the Swift language feature that allows us to define a custom type, that implements behavior from get and set methods, and reuse it everywhere. Declare  @propertyWrapper  keyword before we declare the type that we want to use as property wrapper. It can be  struct ,  class , or  enum . We are required to implement the  wrappedValue  property. Most of the time we declare custom  setter  and  getter  in this property. This property can be a  computed  or  stored  property. Example of @Properywrapper @propertyWrapper struct Capitalized { private(set) var text: String = "" //Declared to store the value var wrappedValue: String { get { return text } set { text = newValue.uppercased() } } } //Now use it struct User{ @Capitalized var userName: String } var user = User() user.userName = "Pawan" print(user.userName) //PAWAN Thanks for reading, Happy Coding  👨‍💻
Continue Reading »

DateFomatter in Swift

Image
Apple Says A formatter that converts between dates and their textual representations. In simple word It is a class that can take a Date, and output a String describing that time/date as its format instructions dictate. In other words, it has a few pretty useful built-in formats, and the capability to accept a custom date format string. It helps to convert date to string and also helps from string to date Example of Date to String let date : Date = Date () let dateFormatter = DateFormatter () dateFormatter . dateFormat = "MM/dd/yyyy" let todaysDate = dateFormatter . string ( from : date ) //Output will be 05/04/2019 Example of String to Date let dateFormatter = DateFormatter () dateFormatter . dateFormat = "MM/dd/yyyy" let dateObj = dateFormatter . dateFromString ( "05/04/2019" ) More formatter Sunday , Apr 07 , 2019 --> EEEE , MMM d , yyyy 07 / 04 / 2019 -
Continue Reading »