What does .$ mean in javascript

user_14093271 0
Viewed 123

I was in the console trying something when i saw that the .$ can be used along with the document object to access the elements. But i don't know what it actually does.

example :- enter image description here

polymer javascript
3 Answers

After some detective work, my guess it is a special Polymer component property:

Automatic node finding

Polymer automatically builds a map of statically created instance nodes in its local DOM, to provide convenient access to frequently used nodes without the need to query for them manually. Any node specified in the element's template with an id is stored on the this.$ hash by id.

I am not familiar with Polymer, and it is very difficult to find (recent) documentation on this property.

However I believe my guess is correct based on the description above and the screen shot below. As you can see, if you add another . after the $ you get a list of suggested properties. These are all ids in the DOM:

enter image description here

user_1170300

I guess that may be any global object under jquery. Exactly, I don't have any experience with .$ but surf the official docs of Jquery, it may help or another possibility is that it is something coming from backend of from database. There may be a lot of reason. Hope, it helps..

user_162616180

This should be a property added to the element but is not anything special.

An example would be like

let a = {};
a.$ = {
  b: 1,
  c: 2
};
console.log(a.$);

This will also give you the object properties of $ in a.

A bonus fun fact is, in Javascript, emoji is also valid as property name, and therefore

let a = {};
a.$ = {
  "": 1,
  "": 2
};
console.log(a.$[""]);

also works

user_125695960
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