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iOS Object-Oriented Swift Properties Getter and Setter Methods

Geert Van Campenhout
Geert Van Campenhout
7,308 Points
Posted by Geert Van Campenhout
Geert Van Campenhout
7,308 Points

I'm stuck on a task in the get & setter part of Object-Oriented Swift. Does anyone know what my code is missing?

I don't know how to move on here..

Temperature.swift 
class Temperature {
    var celsius: Float = 0.0
    var fahrenheit: Float {
        get { 
             return (celsius * 1.8) + 32.0
        }
        set { 
             celsius = (fahrenheit-32)/1.8
        }
    }    
}

2 Answers

Richard Lu
Richard Lu
20,185 Points
Richard Lu
Richard Lu
20,185 Points

Hey Geert,

You need to use the newValue keyword. Otherwise, setting Fahrenheit would never change anything.

class Temperature {
    var celsius: Float = 0.0
    var fahrenheit: Float {
        get { 
             return (celsius * 1.8) + 32.0
        }
        set { 
             celsius = (newValue-32)/1.8  // newValue inserted here
        }
    }    
}

Good luck! :D

Jhoan Arango
Jhoan Arango
14,575 Points
Jhoan Arango
Jhoan Arango
14,575 Points

Hello there

Computed Properties

  • “In addition to stored properties, classes, structures, and enumerations can define computed properties, which do not actually store a value. Instead, they provide a getter and an optional setter to retrieve and set other properties and values indirectly.”

So we know that a computed property is just a read-only property, where you can’t capture the value and use it somewhere else, it ONLY computes something and displays it (if you can say it like that).

class Temperature {
    var celsius: Float = 0.0
    var fahrenheit: Float {
    get {
        return (celsius * 1.8) + 32.0
        }
    set {
        celsius = (newValue - 32)/1.8 
    }
    }    
}

var temp = Temperature()

temp.fahrenheit = 89 // newValue being passed

In this challenge in order for us to set a value to the celsius property we can use the newValue keyword, this will set the value passed through the fahrenheit computed property.

Hope you understand a bit more.