Eloquent Javascript: what is `this` in the following example?

Asked Nov 05 '16 at 15:43

Active Nov 05 '16 at 15:43

Viewed 59 times

Looking into eloquentjavascript, in the section of Objects as interfaces, there is an example:

(Outside of a function, this refers to the global scope object.)

(function(exports) {
  var names = ["Sunday", "Monday", "Tuesday", "Wednesday",
               "Thursday", "Friday", "Saturday"];

  exports.name = function(number) {
    return names[number];
  };
  exports.number = function(name) {
    return names.indexOf(name);
  };
})(this.weekDay = {});

console.log(weekDay.name(weekDay.number("Saturday")));
// → Saturday

What does this refers to the global scope object mean? what is the global scope object here (this)? Confused.

Any comments welcomed. Thanks

asked Nov 05 '16 at 15:43

BAE

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`window` is the global scope object – Andrew Li Nov 05 '16 at 15:44
http://stackoverflow.com/questions/3277182/how-to-get-the-global-object-in-javascript – Mahi Nov 05 '16 at 15:45
In a browser, it's `window`, it's just telling you that `this.weekDay` would be the same as `window.weekDay` in this particular example. – adeneo Nov 05 '16 at 15:50
@adeneo how about in backend? – BAE Nov 05 '16 at 15:52
@BAE probably **global** – JonSG Nov 05 '16 at 16:02
When you run this script in the browser, the global scope is `window`, otherwise, in other evironments (such as node) where there is no `window`, it refers to a global object, accessible from anywhere. – topheman Nov 05 '16 at 16:12

Eloquent Javascript: what is `this` in the following example?

0 Answers0