Regular Expression for subdomain validation in JavaScript

Searching for a specific regex pattern in Javascript to confirm that a hostname is a subdomain and not a top-level domain. Take this scenario:

deny   domain.uk
allow  sub.domain.uk
deny   domain.ac.uk
allow  sub.domain.ac.uk

Answer №1

It may be more effective to use a blacklist and whitelist rather than relying solely on regular expressions in this scenario.

const blackList = ['http://', 'https://'];

const whiteList = ['www.exampledomain.com', 'www.anotherexample.net']

if (blackList.indexOf(domain) < 0 && whiteList.indexOf(domain) >=0)
    console.log('Domain is valid');

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

The attempt to compress the code from this particular file within the node_modules directory was unsuccessful

Hey there! I'm facing an issue while attempting to compile my React project using npm run build. Upon running this command in the console, I encountered the following error message: Failed to minify the code from this file: ./node_modules/react- ...

Ng-outlet is unable to retrieve data from the parent $scope

When using Angular's standard route, I found that child controllers were able to access the parent $scope like this: <div ng-controller="ParentCtrl"> <ng-view></ng-view> </div> However, when switching to the Angular 1.5 C ...

Learn how to efficiently import data into d3.js from several JavaScript arrays, and create a dynamically updating chart without the need to refresh the page

I currently have two arrays: one is a list of numbers called nums, and the other is a list of strings titled places. For example: nums=[1,2,3,4,5] places = ["house","gym", "work", "school", "park"] Both arrays are the same length. I am looking to crea ...

The issue with Node.js arises when attempting to access data within a nested fs.readFile call

This is my initial attempt at a nodejs project and I'm struggling to pinpoint the issue: https://i.sstatic.net/NsI7M.png fs.readFile("/home/shaurya/Desktop/test.txt","utf-8", function(err,filedata1){ fs.readFile(filedata1,"utf-8",function(err, ...

An error occurred while trying to add a property to an array because the object is not extensible: TypeError -

In my code, there is an object named curNode with the following structure: { "name": "CAMPAIGN", "attributes": {}, "children": [] } I am attempting to add a new node to the object like this: curNode!.children!.push({ name: newNodeName, ...

If you encounter an unrecognized operator in Javascript, make sure to handle this error and return

I have a script that identifies operators in an array and uses them to calculate based on another array. Below is the script: function interpret(...args) { let operators = args[1]; //access the operators array let values = args[2] //numbers except t ...

Combine the results of callbacks executed in a loop and return the final concatenated value

I have a dilemma with my data stored in MongoDB. I am currently attempting to update the score whenever it is triggered. However, due to the nature of my task, I find myself needing to execute multiple queries depending on a loop. Ultimately, my goal is t ...

Get geographical coordinates (latitude and longitude) from a database and pass them to a PHP

I have been working on plotting latitude and longitude data from a MySQL database onto a PHP page. Initially, I was able to display the marker without using JSON with the following code: <? $dbname ='insert mysql database name'; ...

Using Ajax and jQuery to dynamically insert an option into a datalist

I'm in the process of building a search box using Flask, MySQL, and ajax. I've managed to retrieve the search results in JSON format within the console, but now I want to dynamically add them to the options in my datalist element in the HTML. He ...

"Revamp your site with Vue and API for dynamic background

I'm faced with an issue where I am attempting to modify the background of a joke fetched from an API, but for some reason, the background is not changing and I can't seem to identify why. The main problem lies in my inability to change the proper ...

Can the Browser Handle Quick Sorting of Enormous XML Data?

Currently, our team is facing a problem due to server restrictions that are beyond our control. We are required to use an XML file and parse it using JavaScript/jQuery instead of utilizing a database for a job. Moreover, we do not have direct write access ...

Is there a distinction in the DOM model and JavaScript between a text box and the content inputted inside it?

Apologies if this is a beginner question, but I'm feeling confused. When I view a page (generated by SSRS in ReportViewer) in Firebug, I see the following: I am trying to find the ID of the input box, however the label displays "_value". Does this me ...

JS receiving a reference to an undefined variable from Flask

I referenced this helpful post on Stack Overflow to transfer data from Flask to a JS file. Flask: @app.route('/') def home(): content = "Hello" return render_template('index.html', content=content) HTML <head> ...

The Homescreen.js file is not showing up as expected on the localhost/home page and is not displaying

Struggling to showcase the rooms on my hotel reservation website. Can't seem to crack it. Need some assistance, please. Spent a good 3 hours trying to figure this out. Snippet from My Homescreen.js import React ,{useState, useEffect, } from &apo ...

Revising Next.js App Components Following User Authentication

I am in the process of integrating a user-based system into my static 2-page Next.js app. To handle authentication, I have chosen Auth0. My main objective is to allow users to view documents they have saved on the app, similar to Grammarly. However, I am f ...

A method for reversing specific characters within lengthy strings

I'm currently tackling a coding problem: For a given string s and an integer k, the task is to reverse the first k characters for every 2k characters starting from the beginning of the string. If there are less than k characters remaining, reverse al ...

The Jquery ajax request fails to function properly once the webpage has been published live

We've implemented a basic jQuery ajax call. A "more" button triggers a call to another PHP file when clicked. While it worked fine on my local server and initially on the live server, it suddenly stopped working live. The code functions perfectly o ...

`html2canvas encountered an issue: Unable to locate a logger instance`

When I use html2canvas to render the same content repeatedly, I encounter an error about 5% of the time. It seems to be sporadic and I'm not sure why it occurs. What could be causing this unpredictable behavior? html2canvas.js:2396 Uncaught (in promi ...

Resizing an image for mobile using next/Image

I have been using next/Image in conjunction with tailwind to display an image as a banner that spans the entire width of its container, which happens to be the full page width. The challenge I am facing is that the image appears distorted and unbalanced o ...

Conceal the loading spinner in JQuery once the image has finished loading

I am working with a jQuery function that captures the URL of an image link and displays the image. However, my issue lies in managing the loading process. I would like to display a LOADING message and hide it once the image has fully loaded, but I am strug ...