CODEWITHSUNDEEP
javascriptprototypesetter
user3719857
user3719857

Reputation: 1123

Use of setter and Object.create();

I'm currently reading the series of books You don't know JS. In one of the books it's written :

If a foo is found higher on the [[Prototype]] chain and it’s a setter (see Chapter 3), then the setter will always be called. No foo will be added to (aka shadowed on) myObject, nor will the foo setter be redefined.

Now I tried the following code:

var a = {
  set t(tet) {
    this._t_ = tet;
  },
  get t() {
    return this._t_ ;
  }
};

a.t = 5;
var b = Object.create(a);
b.t = 4;
console.log(a.t);
console.log(b.t);

For my suprise the logs print out 5 and 4 in that order. From what is written in the book I expect to see two 4 being printed, but it seems there is actually shadowing. Why is that ?

Thanks to the answer by Quentin, this is actually the code that demonstrates the functionallity I wanted :)

var a = { 
  t : undefined, 
  set t(tet) {
    t = tet;
  },
  get t() {
    return  t ;
  }
};

a.t = 5;
var b = Object.create(a);
b.t = 4;
console.log(a.t);
console.log(b.t);

Upvotes: 0

Views: 51

Answers (1)

Quentin
Quentin

Reputation: 943100

The 4 and 5 are stored in _t_ on the two different objects, not in t.

t is still the setter and getter in both cases (although the value of this varies because it is called in the context of two different objects).

Upvotes: 1

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