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Complete example of an object defined using property descriptors for this article: https://itnext.io/enhancing-javascript-objects-with-descriptors-and-symbols-2cdc95e9b422
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// Create "backend" object to hold data for getters and setters on main object | |
const _ = Object.create( null ); | |
Object.defineProperties( | |
_, | |
{ | |
firstname: { | |
value: 'John', | |
writable: true, | |
enumerable: false, | |
configurable: false | |
}, | |
middlename: { | |
value: 'Jack', | |
writable: true, | |
enumerable: false, | |
configurable: false | |
}, | |
lastname: { | |
value: 'Doe', | |
writable: true, | |
enumerable: false, | |
configurable: false | |
} | |
} | |
); | |
// Create main object | |
const dbEntry = Object.create( null ); | |
Object.defineProperties( | |
dbEntry, | |
{ | |
_: { | |
value: _, | |
writable: false, | |
enumerable: false, | |
configurable: false | |
}, | |
id: { | |
value: 1, | |
enumerable: true | |
}, | |
ssn: { | |
value: '123-45-6789', | |
writable: false, | |
enumerable: true, | |
configurable: false | |
}, | |
birthdate: { | |
value: '01/21/1980', | |
writable: false, | |
enumerable: true, | |
configurable: false | |
}, | |
lastAccessed: { | |
value: Date.now(), | |
writable: true, | |
configurable: false, | |
enumerable: true | |
}, | |
lastModified: { | |
value: Date.now(), | |
writable: true, | |
configurable: false, | |
enumerable: true | |
}, | |
name: { | |
enumerable: true, | |
configurable: false, | |
get() { | |
this.lastAccessed = Date.now(); | |
const { firstname, middlename, lastname } = this._; | |
return `${firstname} ${middlename} ${lastname}`; | |
}, | |
set(newName) { | |
this.lastModified = Date.now(); | |
const [ | |
firstname, | |
middlename, | |
lastname | |
] = newName.split(' '); | |
this._.firstname = firstname; | |
this._.middlename = middlename; | |
this._.lastname = lastname; | |
} | |
}, | |
[Symbol.iterator]: { | |
value: function* () { | |
yield this.id; | |
yield this.name; | |
yield this.birthdate; | |
yield this.ssn; | |
yield this.lastAccessed; | |
yield this.lastModified; | |
} | |
}, | |
[Symbol.toPrimitive]: { | |
value: function (hint) { | |
if (hint === 'string') { | |
return [ ...this ].join(', '); | |
} | |
return NaN; | |
} | |
} | |
} | |
); |
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