Where can variables be found within the scope?

Would it be possible to automatically identify all variables within a specific scope? For example:

var localScope = function() {
    var var1 = "something";
    var var2 = "else...";

   console.log(LOCAL_SCOPE);
};

and have LOCAL_SCOPE return an object like this:

{
    var1: "something",
    var2: "else..."
}

I understand that I can manually create a local object to achieve this, but I am interested in a method that automatically identifies all variables without prior knowledge of their existence.

Answer №1

Obtaining all local variables is a challenging task without a foolproof method. The closest approach involves retrieving the source code of the function.

If you are unaware of a reference to the current function, using the deprecated argument.callee (forbidden in ECMAScript 5) becomes necessary.

To access the source code of the function, you can employ the non-standard toSource() method or use .toString().

Once you have the source code as a string, extracting variable names using regular expressions is essential. By combining this technique with iterating through window, you may identify local variables of functions defined within global scopes. However, employing eval is needed to obtain a reference to these variables.


In conclusion, locating all local variables reliably remains a challenge, and it is advised not to pursue such a method as there is no surefire way to accomplish this task.

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

What is the best way to fill a dropdown menu with names and corresponding numeric IDs?

How can I effectively link my dropdown to a variable in the controller, using the id property of the dropdown array instead of the value for assignment? Meanwhile, still displaying the content of the drop down using the name property of the array for user ...

Issue with Mongoose: Create operations are not functioning properly right after performing Delete operations

I need to refresh my collection by deleting all existing documents and then repopulating them with new data from an API call. But when I try running the delete operations first, no new documents are created. Below is a simplified version of my controller ...

Receive JSON data in URL as an array in PHP

What I aim to accomplish is: I have a JSON object structured like below var foo = { format:"json", type:"test", id:"26443" }; and my goal is to convert it into a URL in the following format 'http://example.com/a:3:{s:6:"format";s:4:" ...

What is the best way to recycle Vue and Vuetify code?

<script> export default { data () { return { my_alert: false, text: '', color: 'success' } }, methods: { openAlt (text, color) { this.text = text this.color = color this.my_ale ...

How can users change the displayed Twitch channel?

My coding skills aren't the greatest, especially when it comes to something like this. I've tried searching for a solution with no luck, so I apologize if this is too basic or impossible. I have a simple page that loads up Twitch with a predefin ...

What is preventing Backbone from triggering a basic route [and executing its related function]?

Presenting My Router: var MyRouter = Backbone.Router.extend({ initialize: function(){ Backbone.history.start({ pushState:true }); }, routes: { 'hello' : 'sayHello' }, sayHello: function(){ al ...

Transforming a PHP cURL call to node.js

Currently exploring the possibility of utilizing the Smmry API, however, it seems that they only provide PHP API connection examples. Is there anyone who could assist me in adapting it into a JS request? My requirement is simple - I just need it to analyz ...

How to extract information from a JavaScript object array in Node.js?

Currently, I am attempting to extract data from a JavaScript Object array by providing field names and then storing the data in an array. However, my current approach seems to be yielding incorrect results. Whenever I try to log the values stored in ' ...

Steps for inserting a video into a new div upon selecting a hyperlink

Looking for a way to link menu elements to corresponding videos in adjacent divs? I have two divs set up - one with the menu list and another right next to it where the videos should be loaded. Forms seem like a potential solution, but I lack expertise i ...

In Laravel Blade, I am looking to display a Modal popup and dynamically pass data based on the user's ID

When a user clicks on the "View Details" Button, I need to display a popup modal with information specific to that user. The data for each user is stored in the $user variable. I would like to achieve the same functionality as demonstrated on this website ...

Conceal hyperlink repeatedly using jQuery

I am struggling with implementing a feature where I have two links, one displayed and the other hidden. Upon clicking the first link, it should disappear and the second link should be displayed. Clicking the second link should then hide itself and show the ...

Display information from an array in checkboxes. If the same data appears in another array, the corresponding checkbox in React will be automatically checked

I currently have two arrays. The first array, let's call it arr1, contains multiple objects such as [{"Name":"Mr.X"},{"Name":"Mr.Y"},{"Name":"Mr.Z"}]. The second array, named arr2, holds a few values like [{"Name":"Mr.Z"}]. My goal is to display all ...

What is the best way to replicate the content of the textarea exactly as it is (with all line breaks and special characters)?

Below is the Laravel form I have, and I need to extract the text in a way that retains its original format: <style type="text/css" media="screen"> #editor { position: absolute; top: 150px; right: 150px; bottom: 15 ...

The query limit issue in Sails JS

I am encountering a 413 (Request Entity too large) error when making a request to a Sails Js app (v0.12). Despite my attempts to raise the request limit in the bodyParser, I have not seen any changes take effect. In config/http.js, I included a customize ...

Access JSON value using jQuery by key

Creating a JSON structure that contains information about attendees: { "attendees": [ { "datum": "Tue, 11 Apr 2017 00:00:00 GMT", "name": " Muylaert-Geleir", "prename": "Alexander" }, { "datum": "Wed, 12 Apr 2017 ...

Is it possible to deinitialize data tables (remove from memory)?

I'm currently utilizing data-tables (with jQuery) on my website. The particular data-table I have implemented seems to be consuming excessive memory in javascript, causing a slowdown in other functionalities. Is there a way for me to de-initialize th ...

Using $stateParams injection for unit testing Angular applications with Karma

Here is the starting point for the controller code: angular .module('hc.hotelContent') .controller('NameLocationController', nameLocationCtrlFn); //Todo change hotelDataService nameLocationCtrlFn.$inject = ['$stateParams', &a ...

"Sorting functionality in Amcharts with dynamic movement of the div as the chart scroll bar is used

After exploring the question discussed here, I discovered that using li wasn't the most suitable option for me. Therefore, after further investigation and following the guidance provided in the example here, I successfully managed to create a customiz ...

Utilizing Vue JS for filtering numerical data

When I search for letters, my code below works well. However, when it comes to numbers like flat_number, it gives me an error saying flat.flat_number.toLowerCase is not a function filteredList() { return this.Flats.filter((flat) => { return ( ...

Conceal a div once the content in a separate div has finished loading

After loading an image in slices inside a div, I want to ensure that the entire content is loaded before displaying the div. To achieve this, I am using another div as a mask while the content loads: <div id="prepage" style="position:absolute; left:0px ...