iOS_Interview_Questions_Thermometer.md

#iOS Interview Questions (Thermometer)

Here’s a model of a thermometer as a class and a struct:

public class ThermometerClass {
    private(set) var temperature: Double = 0.0
    public func register(temperature: Double) {
        self.temperature = temperature
    }
}

let thermometerClass = ThermometerClass()
thermometerClass.register(temperature: 56.0)

public struct ThermometerStruct {
    private(set) var temperature: Double = 0.0
    public mutating func register(temperature: Double) {
        self.temperature = temperature
    }
}

let thermometerStruct = ThermometerStruct()
thermometerStruct.register(temperature: 56.0)

This code fails to compile. Where? Why?

Here's the same code in Objective-C

@interface Thermometer : NSObject

@property (nonatomic, strong, readonly) NSNumber *temperature;

- (void)registerTemperature:(NSNumber *)temperature;

@end

@interface Thermometer()

@property (nonatomic, strong, readwrite) NSNumber *temperature;

@end

@implementation Thermometer

- (void)registerTemperature:(NSNumber *)temperature {
    self.temperature = temperature;
}

@end