what is this.e in javascript

Question

I am learning to make library like jquery and trying to understand a piece of code where this.e is giving me hard time, where this 'e' come from and they are assigning object to it but when they return this they return just this not this.e .

function _(a) {
  var b = {
    key: "some val"
  };
  if (a) {
    if (window === this) {
      return new _(a)
    }
    this.e = document.getElementById(a);
    return this
  } else {
    return b
  }
}
_.prototype = {
    hide: function() {
      this.e.style.display = "none";
      return this
    }

HTML

<button onclick="_('abc')">click</button>
<div id="abc" style="width: 200px; height: 100px; background-color: pink;">   </div>

`this.e` comes from `this.e = document.getElementById(a);`. If that doesn't answer your question I think you need to give a bit more details about what part is confusing you, EG. why are you confused about `this.e = X` but not confused about `_.prototype = Y`? — Paul, Nov 01 '16 at 23:45
see: http://stackoverflow.com/questions/13418669/javascript-do-i-need-to-put-this-var-for-every-variable-in-an-object — Ahmad Sanie, Nov 01 '16 at 23:45
You should research dynamic programming language. You can assign anything to an object at run time. — KnowHoper, Nov 01 '16 at 23:47
`.e` is an object property named `e`. `this.foo = 'bar';` --- that's how you set the `'bar'` string to the `foo` property of the `this` object. — zerkms, Nov 01 '16 at 23:47
okeyyy so "this" is an object a built in object and we are adding a property to that object okey gr8 understood — user6920839, Nov 01 '16 at 23:49
@user6920839 Just a heads up, the accepted answer *is wrong*. — Andrew Li, Nov 02 '16 at 04:37

score -3 · Answer 1 · answered Nov 01 '16 at 23:58

-3

It's just a convention to use e as function parameter name when the parameter is event. as in your example here the event is onclick

answered Nov 01 '16 at 23:58

peter

1
5

1

In OP's example, `e` appears to be an element, not an event – Phil Nov 02 '16 at 00:12
This makes no sense at all! `e` is never used as a function parameter, and `e` is not an event! – Andrew Li Nov 02 '16 at 00:27

what is this.e in javascript

1 Answers1