Methods Incorrect Formula


#1

class Surgeon {
constructor(name, department) {
this._name = name;
this._department = department;
this._remainingVacationDays = 20;

}
get name(){
return this._name;
}

get department(){
return this._department;
}

get remainingVacationDays(){
return this._remainingVacationDays;
}

takeVacationDays(daysOff){
// this._remainingVacationDays - daysOff = this._remainingVacationDays;

this._remainingVacationDays = this._remainingVacationDays - daysOff;

}
}

const surgeonCurry = new Surgeon(‘Curry’, ‘Cardiovascular’);
const surgeonDurant = new Surgeon(‘Durant’, ‘Orthopedics’);

My instructions:

Under the remainingVacationDays getter, create a method called takeVacationDays that accepts one argument named daysOff.

Inside of the method, subtract daysOff from the number saved to _remainingVacationDays. Set _remainingVacationDays to the result.

I’m interested in:

takeVacationDays(daysOff){
// this._remainingVacationDays - daysOff = this._remainingVacationDays;

this._remainingVacationDays = this._remainingVacationDays - daysOff;

}
}

The commented line is what I had.
The non-commented line is what I found here in the forums.

I understand that it wants me to take subtract the daysOff from the this._remainingVacationDays and then set this equal to the new this._remainingVacationDays.

Why is that my line of code didn’t work?

Thanks!


#2

Assignments are always from right to left, unlike in algebra where there is a sense of direction…

a + b = c

c = a + b

Both are okay in math, but only the latter is valid in programming.