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Converting CSV data to a list of objects Javascript

I wish to convert a CSV file with data on camping spots to a list of objects. The attributes of the shelters are separated by a semicolon and looks something like this:
X;Y;postnumber_city;name;postnumber;describtion_short;max_number_of_people
445502.7247;6212415.4577;Hvide Sande;Shelter 1;6960;3 shelters, grillplads, borde-/bænkesæt og toilet;6
My code looks like this:
const fs = require('fs');
function csvToObjects(fileName) {
fs.readFileSync(fileName, "utf-8");
let jsObj = [];
let shelters = fileName.split('\n')
for (let attributes of shelters) {
attributes = shelters.split('; ');
}
obj.push(attributes)
}
console.log(csvToObjects('shelters.csv'));
I really don't know what I am doing wrong. I get an error from attributes = shelters.split('; ');
TypeError: shelters.split is not a function

You need to put obj.push(attributes) inside for loops,and use attributes.split('; '); instead of shelters.split('; ')
function csvToObjects(fileName) {
fs.readFileSync(fileName, "utf-8");
let jsObj = [];
let shelters = fileName.split('\n')
for (let attributes of shelters) {
let data = attributes.split(';');
jsObj.push(data)
}
}

I attempted with some other for-loops and assigned a variable for my readfile, which seemed to do the job.
const fs = require('fs');
function csvToObjects(fileName) {
let file = fs.readFileSync(fileName, "utf-8");
let jsObj = [];
let shelters = file.split('\n')
let attributes = shelters[0].split(';')
for (let i = 0; i < shelters.length; i++) {
let data = shelters[i].split(';')
let obj = {};
for (let j = 0; j < data.length; j++) {
obj[attributes[j].trim()] = data[j].trim();
}
jsObj.push(obj);
}
return jsObj;
}

Can't extract Data with For Loop (JavaScript / Fetch)

Why can't I extract the fields that I want from the for loop?
Console Log
JSON Data
document.addEventListener('DOMContentLoaded', function() {
let user = 'example';
fetch(`/jsonresponse/${user}`)
.then(response => response.json())
.then(data => {
// The line below works and prints the username
console.log(data['UsersInfo'][0].username)
// Doesn't work in a for Loop
for (let i = 0; i < data.length; i++) {
console.log(data['UsersInfo'][i].username);
}
});
Any hints would be appreciated

Your issue is in for loop you need to loop over data["UsersInfo"] not just data
vvvvvvvvvvvv
for (let i = 0; i < data["UsersInfo"].length; i++) {
console.log(data["UsersInfo"][i].username);
}
it's better to store user users in array and loop over them with for..of
const users = data["UsersInfo"];
for (const user of users) {
console.log(user.username);
}

Javascript array returned with elements but when logging length I get zero

Trying to get values from an API using async functions. I need to be able to access the values in the array immediately.
componentDidMount() {
var devices = this.props.navigation.state.params.userInfoState.deviceIds
async function call_vstat(device, token) {
try {
let response = await fetch(
'http://app.yatis.io/api/admin/getDeviceStatus?api_access_token=' + token + '&deviceId=' + device,
);
let responseJson = await response.json();
return responseJson;
} catch (error) {
console.error(error);
}
}
var results = []
for (i = 0; i < devices.length; i++) {
var result = call_vstat(devices[i], my_token)
.then( (result) => (results.push(result) ) )
}
console.log(results.length)
console.log(results)
}
Here's the issue when I look at the logger, I get an array of length twenty one but when logging the length itself it shows zero.

If you are using async await you don't have to use the then(). What you can do is
for (i = 0; i < devices.length; i++) {
var result = await call_vstat(devices[i], my_token)
results.push(result)
}
Hope this works

As mentioned in my comments,
var promiseArray = [];
for (i = 0; i < devices.length; i++) {
promiseArray.push(call_vstat(devices[i], my_token));
}
var results = await Promise.all(promiseArray);
if (results.length > 0) {
//perform your business logic after this check to avoid any errors
}

how to set a state within a promise inside a for loop [duplicate]

This question already has answers here:
Waiting for promise in for loop
(2 answers)
Closed 4 years ago.
I have a state this.state = { PathBased : [] , ...ect}
and a function containing a for loop ,after looping this.state.data I want to add every returned element of the for loop to PathBased state ,
I can't find how to do it , could you please help
by the way
console.log(this.state.data) output is 5
async readFromLocal (){
let dirs = RNFetchBlob.fs.dirs;
let path = [];
let leng = this.state.data.length;
if(leng > 0)
{
for( var j = 0 ; j < leng; j++)
{
path[j] = dirs.PictureDir+"/folder/"+this.state.data[j].title;
const xhr = RNFetchBlob.fs.readFile(path[j], 'base64')
.then ((data) => {this.setState({PathBased:[...PathBased,data]})})
.catch ((e) => {e.message});
}
}
console.log(this.state.PathBased.length) // output = 0
}

You could make use of Promise.all and set the final result in the PathBased state. Also since setState is async you need to check the updated state in setState callback.
async readFromLocal (){
let dirs = RNFetchBlob.fs.dirs;
let path = [];
let promises = [];
let leng = this.state.data.length;
if(leng > 0) {
for( let j = 0 ; j < leng; j++) {
path[j] = dirs.PictureDir+"/folder/"+this.state.data[j].title;
promises.push(RNFetchBlob.fs.readFile(path[j], 'base64'))
}
}
Promise.all(promises)
.then(data => this.setState({PathBased: data}, () => {console.log(this.state.PathBased)})
)
.catch(e => {console.log(e.message)});
}

An analog of async.queue for Async/Await functions

I am modernizing some code. It has a piece to load database implemented as:
var customerQueue = async.queue(insertCustomer, DATABASE_PARALLELISM);
customerQueue.drain = function() {
logger.info('all customers loaded');
airportCodeMappingQueue.push(airportCodeMappings);
}
The function insertCustomer used to written with callbacks. I changed it to async/await, as a part of code modernization.
Now, think that I wrote an equivalent of async.queue as:
let customerQueueElements = [];
var customerQueue = {};
customerQueue.push = (customers) => {
customers.forEach(customer => {
customerQueueElements.push(insertCustomer(customer))
});
}
const processQueue = async (queue, parallelism) => {
for (let i = 0; i < queue.length; i += parallelism) {
for (let j = 0; j < parallelism; j++) {
let q = []
if (queue[i + j]) {
q.push(queue[i + j])
}
await Promise.all(q)
}
}
}
I am able now to do await ProcessQueue(customerQueue, DATABASE_PARALLELISM), but the syntax is bad, and I am keeping a visible named variable for each queue.
What would be a good way to handling this?
Also, drain() should be hooked-up to then, right ?

#Bergi is correct, as far as direction. I put together a work-in-process version:
module.exports = function () {
module.internalQueue = []
module.func = undefined
module.parallelism = 1
const process = async () => {
for (let i = 0; i < module.internalQueue.length; i += module.parallelism) {
for (let j = 0; j < module.parallelism; j++) {
let q = []
if (module.internalQueue[i + j]) {
q.push(module.func(module.internalQueue[i + j]))
}
await Promise.all(q)
}
}
module.internalQueue = []
module.drain()
}
module.queue = (func, parallelism = 1) => {
module.func = func
module.parallelism = parallelism
return module
}
module.push = async (customers) => {
module.internalQueue.push(customers)
await process()
}
module.drain = () => {}
return module
}
It is not exactly correct, yet. The signatures are similar to the async package, but my version shares the queue among all instances.
Need to figure out an easy way of creating an instance for each function with a separate e.g. "local" queue. Then, it will basically work like the original one.
Will update as I have progress.