JSON.stringify(dataArray) will always return square brackets because dataArray is of type array. Instead, you could stringify each element of your array, then join them separated by commas.

dataArray = dataArray.map(function(e){
  return JSON.stringify(e);
});

dataString = dataArray.join(",");

Then

["newData",4,2]

becomes

"newData",4,2

Addendum: Please don't try to replace() out the brackets manually because it could be that one day a bracket enters your array in a string. e.g. ["Please see ref[1]",4,2]

If your object looks like:

myObject = {"value": " this is a string"};

You don't need to stringify to get the string value, you can use this instead:

myObject.value

The data just needs a bit of massaging

var data = {
    "question1": {
        "Reliable": true,
        "Knowledgeable": false,
        "Helpful": true,
        "Courteous": true
    },
    "question2": {
        "checked": "Extremely Well"
    },
    "question3": {
        "checked": "Extremely Well"
    },
    "question4": {
        "checked": 3
    },
    "fullName": "Test",
    "address": "Test",
    "city": "Test",
    "state": "Test",
    "zip": "321",
    "areaCode": "321",
    "phone": 1234567896,
    "call": true,
    "lifeInsurance": "Yes",
    "brokerage": "Yes",
    "bankName": "Regions"
};

var result = Object.entries(data).reduce((result, [key, value]) => {
    key = key.replace(/([A-Z]|\d+)/g, ' $1').replace(/^(.)/, (unused, p1) => p1.toUpperCase());
    if (!['string', 'number', 'boolean'].includes(typeof value)) {
        value = Object.entries(value).map(([key, value]) => (typeof value == 'boolean') ? (value ? key : undefined) : value).filter(v => v !== undefined).join(',');
    }
    result.push(`${key}: ${value}`);
    return result;
}, []);
console.log(result.join('\n'));

Note: I changed one of the true to false to check the logic

Tested in node 8.1.2

This simple regular expression solution works to unquote JSON property names in most cases:

const object = { name: 'John Smith' };
const json = JSON.stringify(object);  // {"name":"John Smith"}
console.log(json);
const unquoted = json.replace(/"([^"]+)":/g, '$1:');
console.log(unquoted);  // {name:"John Smith"}

Extreme case:

var json = '{ "name": "J\\":ohn Smith" }'
json.replace(/\\"/g,"\uFFFF");  // U+ FFFF
json = json.replace(/"([^"]+)":/g, '$1:').replace(/\uFFFF/g, '\\\"');
// '{ name: "J\":ohn Smith" }'

Special thanks to Rob W for fixing it.

Limitations

In normal cases the aforementioned regexp will work, but mathematically it is impossible to describe the JSON format with a regular expression such that it will work in every single cases (counting the same number of curly brackets is impossible with regexp.) Therefore, I have create a new function to remove quotes by formally parsing the JSON string via native function and reserialize it:

function stringify(obj_from_json) {
    if (typeof obj_from_json !== "object" || Array.isArray(obj_from_json)){
        // not an object, stringify using native function
        return JSON.stringify(obj_from_json);
    }
    // Implements recursive object serialization according to JSON spec
    // but without quotes around the keys.
    let props = Object
        .keys(obj_from_json)
        .map(key => `${key}:${stringify(obj_from_json[key])}`)
        .join(",");
    return `{${props}}`;
}

Example: https://jsfiddle.net/DerekL/mssybp3k/

Javascript strings are immutable. When you call blah2.replace, you are not replacing something inside blah2, you are creating a new string. What you probably want is:

blah2 = blah2.replace(/[{}]/g, '');

Javascript strings are immutable. When you call blah2.replace, you are not replacing something inside blah2, you are creating a new string. What you probably want is:

blah2 = blah2.replace(/[{}]/g, '');

You can use regex to remove []{} characters: str.replace(/[\[\]\{\}]+/g, '').

You can continue to escape other characters such as quotes if that's what you're looking for.

Use this when you return:

return properties[0];

Or

var data = [

{
    "Name": "TEST",
    "deviceId": "",
    "CartId": "",
    "timestamp": 1383197265540,
    "FOOD": [],
    "City": "LONDON CA"
 }

]; // Or whatever the Json is
data = data[0];

Or if you're accessing the json via another object

var data = jsonObj[0];

change $products[] = to $products = in your for each loop, that should fix the extra square brackets. And if you want to get all entries and their titleVariation fields you should use 'elementType' => Entry::Class

'pricelist/<entryId:\d+>.json' => function($entryId) {
    return [
        'elementType' => Entry::Class,
        'criteria' => [
            'section' => 'products',
            'descendantOf' => $entryId,
        ],
        'transformer' => function(Entry $entry) {

            $products = [];
            // "orderItem" is entry field
            foreach ( $entry->orderItem as $product ) {
                $products = [
                    'title' => $product->titleVariation,
                ];
            }
            return $products;
        },
    ];
},