How can I define an immutable data structure in javascript?

Specifically, how do I define an immutable data structure. For example, I want to define:

const user = {userName: 'user name', password: 'password'}

Such that everywhere it is used or accessed in code:

You cannot change a key
You cannot add or delete a key
You can only change the value associated to that key

The method of defining an immutable data structure should allow for nesting as well so that this structure is also immutable:

const user = {userName: 'user name', password: 'password', permissions: ['login', 'admin'], preferences: {favoriteColor: 'blue'} }

Why would anyone want to do this? Well, it's pretty standard in typing systems and we have real problems with data models in our JS code... we can only see the state via console.log and the structure is mutated all over the place, so devs can never see what should be a super static model and the form data becomes a mess.

Ultimately, how does one define immutable structure one way or another.

I tried everything, nothing seems to provide this need without perhaps typescript?

Via Active questions tagged javascript - Stack Overflow https://ift.tt/YlEh2Bj

Comments

Why is my reports service not connecting?

I am trying to pull some data from a Postgres database using Node.js and node-postures but I can't figure out why my service isn't connecting. my routes/index.js file: const express = require('express'); const router = express.Router(); const ordersCountController = require('../controllers/ordersCountController'); const ordersController = require('../controllers/ordersController'); const weeklyReportsController = require('../controllers/weeklyReportsController'); router.get('/orders_count', ordersCountController); router.get('/orders', ordersController); router.get('/weekly_reports', weeklyReportsController); module.exports = router; My controllers/weeklyReportsController.js file: const weeklyReportsService = require('../services/weeklyReportsService'); const weeklyReportsController = async (req, res) => { try { const data = await weeklyReportsService; res.json({data}) console...

How to show number of registered users in Laravel based on usertype?

i'm trying to display data from the database in the admin dashboard i used this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count(); echo $users; ?> and i have successfully get the correct data from the database but what if i want to display a specific data for example in this user table there is "usertype" that specify if the user is normal user or admin i want to user the same code above but to display a specific usertype i tried this: <?php use Illuminate\Support\Facades\DB; $users = DB::table('users')->count()->WHERE usertype =admin; echo $users; ?> but it didn't work, what am i doing wrong? source https://stackoverflow.com/questions/68199726/how-to-show-number-of-registered-users-in-laravel-based-on-usertype

The number of nodes and edges I calculated manually and by a method provided by networkx library dont match

I am trying to analyse a graph using networkx library in Python. I have implemented a function that returns the nodes and edges of that graph. After that I counted the number of nodes and edges by implementing the len() function for nodes and edges, which gave me 17 for both nodes and edges. However, when I used the method graph.number_of_nodes() of networkx library it gave me 53. My code: import pandas as pd import networkx as nx import matplotlib.pyplot as plt header_list = ["a","b","w"] E =pd.read_csv("aves-barn-swallow-contact-network.edges",sep=" ",header= None,names=header_list) # print(E.head()) # prints first few rows of the csv file G = nx.from_pandas_edgelist(E,"a","b",["w"]) nx.draw(G) plt.show() class GraphAnalyse: #finding nodes and edges def nodeEdge(self,Graph): nodes = Graph.nodes() edges = Graph.edges() ...

StacksPedia

Search This Blog