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How to convert a value too large for integers in JavaScript?

I am fairly new to this and please let me know if I am wrong in any point.
I am trying to convert WEI into Eth, without using the Web3 library.
const weiValue = 100000;
const ethValue = ethers.utils.formatEther(weiValue);<--- answer is correct at 0.0000000000001
My code requires me to change 40000000000000000 wei to eth.
and here is what I have:
const weiValue = 40000000000000000;
const tokenRateString = tokenRate.toString();
const ethValue = ethers.utils.formatEther();
I believe I need to convert the Wei into a string as it too large to be represented accurately as integers in JS
I am confused on what is the intermediate step here

To who ever comes here later.
Yes, a big number such like this : 40000000000000000 need to be a string.
What you need to do is this: 40000000000000000
const WeiToEth = (tokenRate)=> {
const weiValue = BigNumber.from("40000000000000000");
const ethValue = ethers.utils.formatEther(weiValue);
console.log(ethValue) }
It converts the number into a string
Here is the documentation : https://docs.ethers.io/v5/api/utils/bignumber/

How to convert BigQuery Struct Schema string to Javascript object?

I have extracted the schema of my BigQuery table from the "INFORMATION_SCHEMA" table. I get the list of all the columns in the table in a proper Javascript Object format except of the "Struct" and "Array" data types. I need a clean way to convert the "Struct" and "Array" string into a javascript object.
I am working with NodeJS v11.2 I have written a small regex which extracts the following. But it doesn't seem right to split the string and iterate through each word until I get the output. I need a cleaner way to solve this.
let structString = "STRUCT<name STRING, email STRING, time_sec INT64, tz_offset INT64, date STRUCT<seconds INT64, nanos INT64>>";
let _structSchema = structString.match(/STRUCT<([^)]+)>/)[1];
console.log(_structSchema); // name STRING, email STRING, time_sec INT64, tz_offset INT64, date STRUCT<seconds INT64, nanos INT64>
I need to write a recursive function which will parse though the string and give me the output in following manner.
{
"name": "STRING",
"email": "STRING",
"time_sec": "INT64",
"tz_offset": "INT64",
"date": {
"seconds": "INT64",
"nanos": "INT64"
}
}
The function should run irrespective of the depth/hierarchy of the nested structs/arrays.

Using a regex can be good to tokenise the input string, but you'll need more logic to perform the actual parsing.
Here is how you could do it:
function parse(structString) {
let tokenizer = /([a-z_]\w*)|\S|$/gi;
function next(identifier, expected) {
let match = tokenizer.exec(structString);
function error(expected) {
throw `Expected ${expected} but got ${match[0]} at ${match.index}`;
}
match[0] = match[0] || "<EOF>";
if (identifier && !match[1]) error(identifier);
if (expected && !expected.includes(match[0])) error(expected.join(" or "))
return match[0];
}
function getType() {
let fieldType = next("type identifier or STRUCT or ARRAY");
if (fieldType === "STRUCT") {
next(null, ["<"]);
fieldType = {};
do {
fieldType[next("field identifier")] = getType();
} while (next(null, [",", ">"]) === ",");
} else if (fieldType === "ARRAY") {
next(null, ["<"]);
fieldType = [getType()];
next(null, [">"]);
}
return fieldType;
}
let result = getType();
next(null, ["<EOF>"]);
return result;
}
// Sample input & call
let structString = "STRUCT<name STRING, email STRING, time_sec INT64, tz_offset INT64, date STRUCT<seconds INT64, nanos INT64>, phones ARRAY<STRING>>";
let obj = parse(structString);
console.log(obj);

If you can access Google Cloud Console from your environment, consider running something like: bq show --format=pretty project:dataset.table or bq show --format=prettyjson project:dataset.table. You would still need to parse the results for your purposes, but the nesting is already done for you.

Need to format(Indent) invalid JSON String in Javascript. (Best Reference: JSONLINT)

Conside I have a JSON like this(Example: { "abcd":"abcd" ).
I forgot to add braces at the end and its in minified format. I need to convert this into beautify JSON even its invalid using JavaScript like mentioned below
{
\n\t "abcd":"abcd"
Is there any solutions in JavaScript or TypeScript
Actual:
{ "abcd": "abcd","decs": { "jan": 1, "feb" :2 }
Expected:
{
\n\t "abcd": "abcd",
\n\t "decs":
\n {
\n\t\t "jan":1,
\n\t\t "feb":2
\n\t }

I will assume that your JSON is stored in a variable.
let json = '{ "abcd": "abcd","decs": { "jan": 1, "feb" :2 }';
If you don't know what let is, use var.
Then you can do:
json += '}';
And to verify it:
console.log( JSON.parse(json) );

Javascript: Parsing string in csv returns NaN (not a number)

My csv looks like this:
year,dybde,snavn,sfylke
1965,110,Oslo,Sogn og Fjordane
1966,176,Krutå fjellstue,Sogn og Fjordane
1967,86,Ytre Sandsvær,Sogn og Fjordane
This returns NaN for the snavn and sfylke values:
d3.csv("data.csv", function(error, data) {
data.forEach(function(d){
d.year = +d.year;
d.dybde = +d.dybde;
d.snavn = +d.snavn;
d.sfylke = +d.sfylke;
});
sdata = data;
console.log(sdata);
});
I've tried putting the strings in quotes, but it still returns NaN.
Any ideas to point out the mistake would be very much appreciated.

Code something = +strVar always returns NaN - it's impossible to directly convert string to int, so it's Not a Number.
If you want to convert every string to 0, you have to write something = strVar|0.
Or just remove sign + from these lines:
d.snavn = +d.snavn;
d.sfylke = +d.sfylke;

How to replace string values with numeric inside a json object used in google visualization api column chart

I have this Json string that i use for google chart visualization that needs to be in this exact format and i need to replace every value of "v" that is a number to its numeric value( the value without the ""). I should do some javascript replace function, but i couldn't find a way to move around the json object. Here is and example json string that i should modify :
{"cols":[
{"id":"r","label":"Reason","type":"string"},
{"id":"m","label":"Minutes","type":"number"}
],
"rows":[
{"c":[
{"v":"Flour - Blower","f":"Flour - Blower"},
{"v":"7","f":"7"}]},
{"c":[
{"v":"Whole Line - d","f":"Whole Line - d"},
{"v":"4","f":"4"}]},
{"c":[
{"v":"Flour - Pipework","f":"Flour - Pipework"},
{"v":"3","f":"3"}]},
{"c":[
{"v":"Horseshoe - Belt","f":"Horseshoe - Belt"},
{"v":"1","f":"1"}]}
],
"p":null
}
probably i should do something like :
var jsonStr = ...;
for (i in jsonStr.rows) {
for(j in jsonStr[i].c)
{
if (parseInt(jsonStr[i].c[j].v) != 'NaN') {
jsonStr.rows[i].c[j].v = parseInt(jsonStr.rows[i].c[j].v);
}
}

Since JSON is effectively a string, why not put the entire string through a global string.replace:
jsonStr = JSON.stringify(jsonStr);
jsonStr = jsonStr.replace(/"v":"(\d+)"/g, '"v":$1');
Jsfiddle demo

Well, the parsing seems okay to me. It's probably not working because you can't really check if a string contains a number or not by comparing something with NaN
This is because even NaN === NaN, famously, returns false.
I'd suggest that you use the isNaN method (which does use parseInt internally). So, something like this ought to work
for (i in jsonStr.rows) {
for(j in jsonStr[i].c)
{
if (!isNaN(jsonStr[i].c[j].v)) {
jsonStr.rows[i].c[j].v = parseInt(jsonStr.rows[i].c[j].v);
}
}

A function that returns string if isNaN else a number:
function convertNumberToInteger(val) {
if (isNaN(val)) {
return val;
} else {
return parseInt(val);
}
}
Usage:
convertNumberToInteger("sasdfasdf");
Output: "sasdfasdf"
convertNumberToInteger("3");
Output: 3
And if you really want to parse it you can do a forEach on the JSON object