If value is not a plain array, such code will work fine:

var value = { "aaa": "111", "bbb": "222", "ccc": "333" };
var blkstr = [];
$.each(value, function(idx2,val2) {                    
  var str = idx2 + ":" + val2;
  blkstr.push(str);
});
console.log(blkstr.join(", "));
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>

(output will appear in the dev console)

As Felix mentioned, each() is just iterating the array, nothing more.

Answer from user447356 on Stack Overflow
🌐
Tabnine
tabnine.com › home › array to string in javascript
Array to String in JavaScript - Tabnine
July 25, 2024 - JavaScript’s toString() method operates on a given object, returning its text representation as a string. Applying the toString() method to an array returns the values in the array as a string.
Discussions

jquery - Convert javascript array to string - Stack Overflow
In JavaScript, every object is an associative array, including plain array. So to make it more simple I just used "not a plain array" and I stand by this definition. And the answer is correct, it iterates the keys, and collecting the data into plain array that is later converted to string. More on stackoverflow.com
🌐 stackoverflow.com
How do I convert an array to a string with commas in JavaScript
...you get a better, more thorough explanation here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/join More on reddit.com
🌐 r/JavaScriptTips
1
4
April 13, 2023
Adding a new line to an array of strings
Ha! I was literally just commenting about this problem right before I read your post. A single-element string array may become represented as a string due to handy shortcuts behind-the scenes. Due to other handy shortcuts, that string may then be treated as a character array causing this behavior. TL;DR one way to fix this is [string[]]$finalText += "LifeBook Total: $totalLifeBook", "Precision Workstation T7400 Total: $totalWorkstationT7400" Edit: The trick is explicitly casting $finalText as a string array [string[]] so the additions are string elements and not character elements to append to the single string. Also I'm adding two comma-separated string elements as the plus sign would concatenate the strings. More on reddit.com
🌐 r/PowerShell
7
5
January 13, 2017
How do I send a JS variable to flask?

Maybe add an ajax call to your javascript? https://jsfiddle.net/2d3n5pyv/ Something link this on the backend?

  from flask import request
@app.route('/your/flask/endpoint', methods=['POST'])
def get_names():
   if request.method == 'POST':
	   names = request.get_json()
		   for name in names:
			print name			
	return '', 200
More on reddit.com
🌐 r/flask
4
1
June 13, 2017
🌐
W3Schools
w3schools.com › jsref › jsref_tostring_array.asp
JavaScript Array toString() Method
The toString() method returns a string with array values separated by commas. The toString() method does not change the original array. Every JavaScript object has a toString() method.
🌐
CodingNomads
codingnomads.com › javascript-array-to-string-conversion
JavaScript Array-String Conversion
Learn how to seamlessly convert between arrays and strings in JavaScript using methods like .join(), .split(), and more.
🌐
ReqBin
reqbin.com › code › javascript › ot8wzla9 › javascript-array-to-string-example
How do I convert array to string in JavaScript?
November 21, 2023 - You can also create a multiline string, check if it starts or ends with another string, and get the length of a string. In JavaScript, you can convert an array to a string using the Array.join(separator) and array.toString() methods.
🌐
MDN Web Docs
developer.mozilla.org › en-US › docs › Web › JavaScript › Reference › Global_Objects › Array › join
Array.prototype.join() - JavaScript - MDN Web Docs
4 days ago - The join() method of Array instances returns a new string that is the concatenation of all elements in this array, separated by commas or a specified separator string. If the array has only one item, that item's stringification is returned without using the separator.
Find elsewhere
🌐
Scaler
scaler.com › home › topics › array to string in javascript
Array to String in JavaScript - Scaler Topics
January 8, 2024 - How to convert such an array into a string? toString() flattens the array. Thus all the elements of the array, including the nested array elements, get combined into a single array. And that's how we get the new array having all the elements separated by a comma.
🌐
GeeksforGeeks
geeksforgeeks.org › javascript-program-to-convert-an-array-into-a-string
JavaScript Program to Convert an Array into a String | GeeksforGeeks
June 28, 2024 - Example: In this example, The JavaScript function `arrayToString` iterates through each element of the input array using a for loop. It concatenates each element to a result string.
🌐
sebhastian
sebhastian.com › javascript-array-string
Convert a JavaScript array to string | sebhastian
February 1, 2023 - To easiest way to convert a JavaScript array to string is to use the built-in Array method called toString().
🌐
GeeksforGeeks
geeksforgeeks.org › javascript › convert-array-to-string-in-javascript
Convert Array to String in JavaScript - GeeksforGeeks
July 23, 2025 - The foreach() method of JavaScript calls a callback function and performs operations specified on each and every element. Basically, it neither creates new array nor modifies the original array. It basically performs operations on each and every element. Here, in this approach the foreach() method iterates over each and every element and manually concatenates them into the string. This type of method is very useful when one needs to build a string manually with the specific logic for each and every element.
🌐
Alma Better
almabetter.com › bytes › articles › array-to-string-javascript
How to Convert Array to String in JavaScript
June 20, 2024 - For instance, you might want to display the array's contents as a single string in a user interface, send it over a network, or save it in a text file. JavaScript provides several methods to convert an array to a string.
🌐
Will Vincent
wsvincent.com › javascript-convert-array-to-string
JavaScript: Convert Array to a String | Will Vincent
January 3, 2018 - That is, an array with an array inside it? Here you need to use JSON.stringify().
🌐
Favtutor
favtutor.com › articles › convert-array-to-string-javascript
Convert Array to String JavaScript (5 Easy Methods)
November 25, 2023 - There are times when you need to convert array to string without losing the array structure. JavaScript provides the JSON.stringify() method, which converts JavaScript objects, including arrays, to JSON strings.
🌐
YouTube
youtube.com › watch
JavaScript Basics - How To Convert An Array Into A String - YouTube
In this tutorial I'll show you how to convert an array into a string in JavaScript.-------------------------------------------------------------------All my ...
Published: November 18, 2024
🌐
Medium
medium.com › @louistrinh › converting-arrays-to-strings-in-javascript-4d1bbea80c20
Converting Arrays to Strings in JavaScript | by Louis Trinh | Medium
November 20, 2024 - You can use template literals to create a String from an Array. Spread syntax helps convert an Array to a list of arguments. ... JavaScript enthusiast here, sharing knowledge & building awesome things. If my articles fuel your projects, consider a coffee!
🌐
Vultr Docs
docs.vultr.com › javascript › standard-library › Array › toString
JavaScript Array toString() - Convert Array to String | Vultr Docs
September 27, 2024 - The toString() method in JavaScript provides an efficient way to convert an array into a string representation. This method is part of the Array prototype, and it offers a straightforward approach to creating a comma-separated string from an ...
🌐
Reddit
reddit.com › r/javascripttips › how do i convert an array to a string with commas in javascript
r/JavaScriptTips on Reddit: How do I convert an array to a string with commas in JavaScript
April 13, 2023 -

In JavaScript, you can convert an array to a string with commas using the join()
method.

The join() method returns a string that concatenates all the elements of an array, separated by the specified separator, which in this case is a comma.

Here is an example:

const array = ['apple', 'banana', 'orange'];
const string = array.join(', ');
console.log(string); 

// output: "apple, banana, orange"

In this example, we first define an array of three fruits. Then we use the join()
method with a comma and a space as the separator to create a string that lists all the fruits with a comma and a space between each one.

You can replace the comma and space separator with any other separator you like, such as a hyphen, a semicolon, or a newline character.

It's important to note that the join() method only works on arrays, and it will throw an error if you try to use it on any other type of object.

Click here to learn more ways to Convert Array to String with Commas in JS

🌐
DEV Community
dev.to › mehmehmehlol › from-string-to-array-to-string-f67
From String to Array to String - DEV Community
April 23, 2021 - To be more specific, this method joins the array and returns one string containing each array element separated by commas. Fun fact: JavaScript calls the toString method automatically when an array is to be represented as a text value or when ...
🌐
Mastering JS
masteringjs.io › tutorials › fundamentals › array-tostring
Array toString() in JavaScript - Mastering JS
December 8, 2021 - The toString() method returns the elements of the array as a single string without square brackets [ and ]. const array = [1,2,3,4,5]; array.toString(); // "1,2,3,4,5"