JavaScript ES 2020 Tips: The .matchAll() Method

While I take a break from my RegEx series,I wanted to write an article that was still related to regular expressions.I recently learned about the .matchAll()method, which I had not used until this past week.

I had mentioned in this article how to match a pattern and extract it into an array using the .match() method. You’ll see that .matchAll() works similarly to .match() with slight differences.

#programming #nodejs #javascript #react #node

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JavaScript ES 2020 Tips: The .matchAll() Method
Brain  Crist

Brain Crist


Citrix Bugs Allow Unauthenticated Code Injection, Data Theft

Multiple vulnerabilities in the Citrix Application Delivery Controller (ADC) and Gateway would allow code injection, information disclosure and denial of service, the networking vendor announced Tuesday. Four of the bugs are exploitable by an unauthenticated, remote attacker.

The Citrix products (formerly known as NetScaler ADC and Gateway) are used for application-aware traffic management and secure remote access, respectively, and are installed in at least 80,000 companies in 158 countries, according to a December assessment from Positive Technologies.

Other flaws announced Tuesday also affect Citrix SD-WAN WANOP appliances, models 4000-WO, 4100-WO, 5000-WO and 5100-WO.

Attacks on the management interface of the products could result in system compromise by an unauthenticated user on the management network; or system compromise through cross-site scripting (XSS). Attackers could also create a download link for the device which, if downloaded and then executed by an unauthenticated user on the management network, could result in the compromise of a local computer.

“Customers who have configured their systems in accordance with Citrix recommendations [i.e., to have this interface separated from the network and protected by a firewall] have significantly reduced their risk from attacks to the management interface,” according to the vendor.

Threat actors could also mount attacks on Virtual IPs (VIPs). VIPs, among other things, are used to provide users with a unique IP address for communicating with network resources for applications that do not allow multiple connections or users from the same IP address.

The VIP attacks include denial of service against either the Gateway or Authentication virtual servers by an unauthenticated user; or remote port scanning of the internal network by an authenticated Citrix Gateway user.

“Attackers can only discern whether a TLS connection is possible with the port and cannot communicate further with the end devices,” according to the critical Citrix advisory. “Customers who have not enabled either the Gateway or Authentication virtual servers are not at risk from attacks that are applicable to those servers. Other virtual servers e.g. load balancing and content switching virtual servers are not affected by these issues.”

A final vulnerability has been found in Citrix Gateway Plug-in for Linux that would allow a local logged-on user of a Linux system with that plug-in installed to elevate their privileges to an administrator account on that computer, the company said.

#vulnerabilities #adc #citrix #code injection #critical advisory #cve-2020-8187 #cve-2020-8190 #cve-2020-8191 #cve-2020-8193 #cve-2020-8194 #cve-2020-8195 #cve-2020-8196 #cve-2020-8197 #cve-2020-8198 #cve-2020-8199 #denial of service #gateway #information disclosure #patches #security advisory #security bugs

Ray  Patel

Ray Patel


top 30 Python Tips and Tricks for Beginners

Welcome to my Blog , In this article, you are going to learn the top 10 python tips and tricks.

1) swap two numbers.

2) Reversing a string in Python.

3) Create a single string from all the elements in list.

4) Chaining Of Comparison Operators.

5) Print The File Path Of Imported Modules.

6) Return Multiple Values From Functions.

7) Find The Most Frequent Value In A List.

8) Check The Memory Usage Of An Object.

#python #python hacks tricks #python learning tips #python programming tricks #python tips #python tips and tricks #python tips and tricks advanced #python tips and tricks for beginners #python tips tricks and techniques #python tutorial #tips and tricks in python #tips to learn python #top 30 python tips and tricks for beginners

Niraj Kafle


The essential JavaScript concepts that you should understand

As a JavaScript developer of any level, you need to understand its foundational concepts and some of the new ideas that help us developing code. In this article, we are going to review 16 basic concepts. So without further ado, let’s get to it.

#javascript-interview #javascript-development #javascript-fundamental #javascript #javascript-tips

Julie  Donnelly

Julie Donnelly


JavaScript Promise: Methods Comparison


Promises in JavaScript are used to handle asynchronous operations by keeping track of whether a certain event has happened. If that certain event has taken place, it determines what happens next. Promises return a value which is either a resolved value or a reason why it’s rejected. They can handle multiple asynchronous operations easily and they provide better error handling than callbacks and events.

Callback: A callback is a function that is passed into another function as an argument to be executed later.

Events: Events provide a dynamic interface to a WebPage and are connected to elements in the Document Object Model(DOM), for example: onclick(), onmouseover() etc.

A Promise has four states

Pending: Before the event has happened, the promise is in the pending state.

Settled: Once the event has happened it is then in the settled state.

Fulfilled: Action related to the promise has succeeded.

Rejected: Action related to the promise has failed.

#javascript #javascript-development #javascript-tutorial #promises #javascript-tips

Grokking Call(), Apply() and Bind() Methods in JavaScript

These functions are very important for every JavaScript Developer and are used in almost every JavaScript Library or Framework. Check out the code snippet below.

Taken from the very popular library Lodash

	* Creates a function that invokes `func` with arguments reversed.
	* @since 4.0.0
	* @category Function
	* @param {Function} func The function to flip arguments for.
	* @returns {Function} Returns the new flipped function.
	* @see reverse
	* @example
	* const flipped = flip((...args) => args)
	* flipped('a', 'b', 'c', 'd')
	* // => ['d', 'c', 'b', 'a']
	function flip(func) {
	  if (typeof func !== 'function') {
	    throw new TypeError('Expected a function')
	  return function(...args) {
	    return func.apply(this, args.reverse())

	export default flip

Look at the statement on line 21, return func.apply(this, args.reverse())

In this article, we will have a look at the call()apply() and bind() methods of JavaScript. Basically these 3 methods are used to control the invocation of the function. The call() and apply() were introduced in ECMAScript 3 while bind() was added as a part of ECMAScript 5.

Let us start with an example to understand these.

Suppose you are a student of X university and your professor has asked you to create a math library, for an assignment, which calculates the area of a circle.

const calcArea = {
	  pi: 3.14,
	  area: function(r) {
	    return this.pi * r * r;

calcArea.area(4); // prints 50.24

You test this and verify its result, it is working fine and you upload the library to portal way before the deadline ends. Then you ask your classmates to test and verify as well, you come to know that that your result and their results mismatches the decimals precision. You check the assignment guidelines, Oh no! The professor asked you to use a constant **pi** with 5 decimals precision. But you used **3.14** and not **3.14159** as the value of pi. Now you cannot re-upload the library as the deadline date was already over. In this situation, **call()** function will save you.

#js #javascript-development #javascript #javascript-interview #javascript-tips