Javascript
Can setter used to validate parameter when creating new object, as seen on this code, the string input on numberOfStudents bypass the setter
class School {
constructor(name, level, numberOfStudents) {
this._name = name;
this._level = level;
this._numberOfStudents = numberOfStudents;
}
get numberOfStudents() {
return this._numberOfStudents;
}
set numberOfStudents(value) {
if (isNaN(value)) {
console.log('Invalid input: numberOfStudents must be set to a Number.');
} else {
return (this._numberOfStudents = value);
}
}
}
const primaryOne = new School('Primary One', 'L1', 'ten');prints
School { _name: 'Primary One', _level: 'L1', _numberOfStudents: 'ten' }
Please help
You're bypassing the validation because you're assigning to the internal _numberOfStudents property. The setter is only run when you assign to numberOfStudents. So change the constructor to do that:
class School {
constructor(name, level, numberOfStudents) {
this._name = name;
this._level = level;
this.numberOfStudents = numberOfStudents;
}
get numberOfStudents() {
return this._numberOfStudents;
}
set numberOfStudents(value) {
if (isNaN(value)) {
console.log('Invalid input: numberOfStudents must be set to a Number.');
} else {
this._numberOfStudents = value;
}
}
}
const primaryOne = new School('Primary One', 'L1', 'ten');