What is $this here in this JavaScript?

Question

I'm looking at JavaScript that produces:

enter image description here

The related code is

enter image description here

My question is, what does $this refer to? Just the keyword "this" I understand, but $this? There doesn't seem to be any jQuery around.

Thanks for any illumination.

possible duplicate of [JavaScript "this" keyword](http://stackoverflow.com/questions/3127429/javascript-this-keyword) — Lucky Soni, Dec 05 '13 at 23:11
same as any other variable - it could be named `someVarName`. nothing special about it. — tckmn, Dec 05 '13 at 23:12
Btw, I love the (probably unintended) pun in the title "What is $this here in **this** JavaScript?". — Max Truxa, Dec 05 '13 at 23:43

score 5 · Accepted Answer · answered Dec 05 '13 at 23:11

It has to do with the Google "jstemplate" mechanism.

From that page:

$this: $this refers to the JsEvalContext data object used in processing the current node. So in the above example we could substitute $this.end for end without changing the meaning of the jscontent expression. This may not seem like a very useful thing to do in this case, but there are other cases in which $this is necessary. If the JsEvalContext contains a value such as a string or a number rather than an object with named properties, there is no way to retrieve the value using object-property notation, and so we need $this to access the value.

score 1 · Answer 2 · answered Dec 05 '13 at 23:13

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It appears to be prefixed with $ due to using the Google JSTemplate API.

More information here: http://code.google.com/p/google-jstemplate/wiki/HowToUseJsTemplate

answered Dec 05 '13 at 23:13

Coder101101010

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score 1 · Answer 3 · answered Dec 05 '13 at 23:14

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That is not javascript, it’s HTML.

What you see is a custom element property called jsdisplay that has the value of $this.something. What it actually does is very hard to give an exact answer to, but as some other pointed out it’s probably used internally in google templating.

answered Dec 05 '13 at 23:14

David Hellsing

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I think it's safe to assume that the **js** display attribute is used for JS :P – tckmn Dec 05 '13 at 23:15
@Doorknob maybe, but the entire question is based on a false assumption that the code is javascript. It might as well be SEO-bogus HTML or microformats, you can’t tell for sure. – David Hellsing Dec 05 '13 at 23:16

score 1 · Answer 4 · edited May 23 '17 at 12:03

Pointy is right for this specific case.

To clear up the confusion about $ in JavaScript:

In JavaScript the dollar sign ($) in variable names is treated like a-z, A-Z and underscore (_).

The variable you are looking at, could have been named anything else. $this is no special JS keyword. The developers of jstemplate could have named it foo if they wanted to. Or like they did, something similar to this, like _this or self.

What is $this here in this JavaScript?

4 Answers4