The Goal: Use the class keyword to create a Thermostat class. The constructor accepts a Fahrenheit temperature. In the class, create a getter to obtain the temperature in Celsius and a setter to set the temperature in Celsius.
Here's my code so far:
class Thermostat {
constructor(fahrenheit){
this.fahrenheit = fahrenheit;
}
get temperature(){
const inCelcius = 5/9 * (this.fahrenheit - 32) ;
return inCelcius;
}
set temperature (temperatureInCelcius){
this.fahrenheit = temperatureInCelcius;
}
}
const thermos = new Thermostat(76); // Setting in Fahrenheit scale
let temp = thermos.temperature; // should show 24.44 in Celsius
console.log(temp);
thermos.temperature = 26;
temp = thermos.temperature; // should show 26 in Celsius but right now showing -3.333
console.log(temp);
I know the correct solution is to change this.fahrenheit = temperatureInCelcius;
into this.fahrenheit = (celsius * 9.0) / 5 32;
But I don’t understand why. I've been told that my code is missing a conversion.
My questions are:
- Why is there a need to convert Fahrenheit into celsius?
- What exactly happens in this line?
thermos.temperature = 26;
My understanding is that when the compiler sees that line, it invokes this line inside the constructor
set temperature (temperatureInCelcius){
this.fahrenheit = temperatureInCelcius;
}
and then put 26 into the argument (temperatureInCelcius)
, then set the property value of this.fahrenheit
to 26.
Just want some explanation cause it feels like I am missing something. Would greatly appreciate your help! <3
CodePudding user response:
When you do temp = thermos.temperature;
, get temperature()
is called and for thermos.temperature = 26;
set temperature()
is called.
// thermos.temperature = 76
const thermos = new Thermostat(76);
// this calls get temperature() and return 24.44
// 5/9 * (76 - 32) = 24.44
let temp = thermos.temperature;
console.log(temp); // 24.44
// this calls set temperature() and sets thermos.temperature = 26
thermos.temperature = 26;
// this calls get temperature() and return -3.333
// 5/9 * (26 - 32) = -3.333
temp = thermos.temperature;
console.log(temp); // -3.33