In javascript, is it okay to use properties in the place of variables?

Question

I'm writing a javascript file where the variable with revealing pattern is destroyed in the end.

var variable = function () {
  var data = 3;

  function getme () {
    return data;
  }

  return {
    fdata: data,
    me: getme
  };
}();

As there is no in-built delete option for variables, is it ok to replace it with property like this.

this.variable = function () {
  var data = 3;

  function getme() {
    return data;
  }

  return {
    fdata: data,
    me: getme
  };
}();

Because, properties are deletable with delete property_name. Will this break the programming pattern and is it a valid way of coding??.

In both examples, `data` is in a different scope and will not be accessible to the return statement. The function `variable` (whether a property or not) is never called. — evolutionxbox, May 30 '17 at 11:32
So declaring property for global context and creating a variable in global scope are the same? Aren't there any difference at all? I'm just curious — Siva Black Jester, May 30 '17 at 11:52
What global variables? You're examples don't have any global variables, and you've removed the property example. — evolutionxbox, May 30 '17 at 11:54
But this is the way to create them.https://stackoverflow.com/questions/12692887/are-the-terms-global-property-and-global-variable-synonyms — Siva Black Jester, May 30 '17 at 12:08

Fahmi · Answer 1 · 2017-05-30T12:55:19.453

0

Say you have a global variable foo and you want to delete it. You can't just delete since it only works for properties.

What you can do is explicitly declare a global variable:

window.foo = 'bar'; // this == window (if not in any function)

Then you can delete:

delete window.foo;

Now if you try to access it you will get:

console.log(foo) // ReferenceError
console.log(window.foo) // undefined

You can't just define with var foo otherwise the deletion won't work.

Anyway if I were you I won't bother "deleting" variables since the garbage collector will handle that.

edited May 30 '17 at 12:55

answered May 30 '17 at 12:45

Fahmi

2,607
1
20
15

Both window.foo and this.foo are the same – Siva Black Jester May 30 '17 at 13:24
Depends, if you're in strict mode, then `this` in a function equals `undefined` unless you use `bind`, `call` etc. – Fahmi May 30 '17 at 14:09

Siva Black Jester · Answer 2 · 2017-05-30T13:45:21.403

http://webcache.googleusercontent.com/search?q=cache:auElwuFsub0J:perfectionkills.com/understanding-delete/+delete+javascript&cd=2&hl=en&ct=clnk

Difference between variable declaration syntaxes in Javascript (including global variables)?

Thanks to these posts, i feel a lot clear now. var x and this.x both create properties of global objects only difference being former sets x's 'DontDelete' attribute to false whereas latter sets it to true.

For much internal details, former keeps track of that variable in 'Declarative environment record' and the latter does the same in 'Object environment record' (What really is a declarative environment record and how does it differ from an activation object?)

score -1 · Answer 3 · answered May 30 '17 at 11:52

-1

Both code are same.

Indeed when you create a var in JS, this is attached to the window object (or this if you are out of any function).

var test = 1;
alert(test);
this.test = 2
alert(test);
window.test = 3;
alert(test);

answered May 30 '17 at 11:52

Kashkain

513
4
11

This doesn't answer the OP's question, as in the example given the variable is created within a function. – evolutionxbox May 30 '17 at 11:53

In javascript, is it okay to use properties in the place of variables?

3 Answers3