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Nodejs determines whether the agent is available

With the popularity of the Internet, the demand for using proxies is also increasing. Understanding whether the proxy is available is a very important step. It is related to whether we can safely use the proxy to surf the Internet. This article will introduce how to use Node.js to determine whether the proxy is available. 1. What is a proxy? A proxy is a method of network communication. In layman's terms, it is a middleman who forwards our requests to the server and then returns the response to us. Proxies can be divided into forward proxies and reverse proxies. Forward proxy means that the client sends the request to the proxy, and then the proxy sends it to the target server.

May 28, 2023 pm 02:11 PM

How nodejs triggers events

Node.js is a JavaScript running environment based on the Chrome V8 engine. It uses an event-driven, non-blocking I/O model, which enables it to demonstrate strong performance and stability when processing high concurrency and large-scale data. In Node.js, event-driven is very important, so this article will introduce in detail how nodejs triggers events. Event-driven In Node.js, every object is an instance of EventEmitter, which is owned by Node.js

May 28, 2023 pm 02:03 PM

Nodejs cannot get the address

Node.js cannot obtain geographic address In many web applications, geolocation information is required. For example, a visitor's location information can be used to display local weather, nearby businesses, and more. Node.js is a powerful tool that can help us obtain and process geolocation information. But sometimes we may find that we cannot obtain geographical location information. What should we do in this case? First, we need to understand how location information is obtained. The most common methods of obtaining geographic location are through the Global Positioning System (GPS) or the Internet Protocol (

May 28, 2023 pm 01:59 PM

Convert numerical value to string in nodejs

In Node.js, numeric values (such as integers or floating point numbers) can be easily converted to strings. In this article, we will introduce several ways to convert numeric values to strings and the differences between them. 1. toString() The simplest method is to use the toString() method. This method can convert any numeric value into a string. For example: ```javascriptlet num = 123;console.log(num.toString()); // "123"`

May 28, 2023 pm 01:33 PM

Install nodejs in the project

Node.js is a JavaScript running environment built on the Chrome V8 engine. It allows JavaScript to run on the server side and has efficient I/O operations, event-driven and asynchronous processing capabilities. In modern web development, Node.js has become one of the essential technologies. It is also very important to install Node.js in the project. This article will introduce how to install Node.js in the project and configure the environment. 1. Install Node.js1. Download Node.js first.

May 28, 2023 pm 01:31 PM

Nodejs implements file upload name

Size and size restrictions With the continuous development of the Internet, file upload has become one of the necessary functions of many websites. In Node.js, file uploads can be implemented using a variety of modules and technologies. Below, we will introduce a file upload method based on the Express framework and discuss how to implement size and name restrictions on file uploads. 1. Install dependent modules In this article we will use the Express framework as the web server and use the multer module to handle file uploads. Let’s install these dependent modules first: ```npm i

May 28, 2023 pm 01:29 PM

nodejs installation and environment configuration linux

Node.js is a very popular server-side JavaScript runtime environment that runs on the V8 JavaScript engine, which is the JavaScript engine in Google Chrome. It enables the JavaScript language to have I/O operation capabilities, and can develop high-performance and scalable network applications through JavaScript programming on the server side. Node.js can run on multiple operating system platforms, including Windows, macO

May 28, 2023 pm 01:29 PM

nvm delete nodejs

NVM is a very commonly used node.js version management tool that allows you to install multiple versions of Node.js on the same computer and easily switch between different projects. However, sometimes you may need to completely remove Node.js and NVM from your computer. This article will show you how to remove Node.js and NVM on Mac and Windows using the command line. 1. How to remove Node.js and NVM on Mac Step 1: Uninstall NVM using the following command: curl -o- https

May 28, 2023 pm 12:51 PM

Nodejs implements short links

With the development of the Internet, short links have become a very popular form of link. Short links can not only shorten the link length, but also beautify the link and increase user click-through rate. This article will introduce how to implement short links with Node.js. 1. What is a short link? A short link is actually a string of characters, corresponding to a long link. The advantage of short links is that they can reduce link length, beautify links and increase user click-through rates. Usually, short link services are provided by a third party, which generates a short link based on the user's long link and then redirects to the original long link address. Such services include

May 28, 2023 pm 12:47 PM

nodejs settings Taobao

Node.js is an open source JavaScript runtime environment based on the Chrome V8 engine, designed to efficiently write scalable web applications. However, some users may experience slow download speeds when installing Node.js packages. The reason for this problem is the lack of reliable download sources, so in this article, we will introduce how to use Taobao NPM mirror to speed up the download of Node.js software package. Step One: Install Node.js Before you begin, you need to install the Node.js runtime environment

May 28, 2023 pm 12:11 PM

When to use callbacks in nodejs

Node.js is a very popular platform for building fast, scalable web applications. As an event-driven technology, Node.js implements non-blocking I/O operations very well through callback functions. However, sometimes we wonder, how to decide when to use callbacks? In this article, we will discuss callbacks in Node.js and when to use callback functions. What is the callback? A callback is a function that is executed after the asynchronous function completes successfully. This means that when we need to perform asynchronous operations, we can put a callback function

May 28, 2023 pm 12:10 PM

How to uninstall nodejs and clear configuration

Node.js is a very popular back-end JavaScript running environment. It is very powerful and can be used to develop server-side applications, command line tools, etc. However, when we need to clean or uninstall Node.js, we may encounter many problems. In order to solve these problems, this article will introduce how to uninstall Node.js and clear its related configuration. 1. Uninstall Node.js To uninstall Node.js, we can use the uninstall tool provided by the system or delete the files manually. In Windows systems, you can use the "Control Panel"

May 28, 2023 pm 12:06 PM

What basics are needed to learn nodejs

Node.js is a server-side runtime environment written in JavaScript. It allows JavaScript developers to write back-end applications using JavaScript on the server side, providing more and more flexible options for full-stack development. To learn Node.js, you need to master certain basic knowledge. The following are some basics you need to master to learn Node.js: 1. JavaScript basics The development language of Node.js is JavaScript.

May 28, 2023 pm 12:01 PM

How nodejs runs html files

With the development of front-end technology, more and more websites adopt dynamic front-end rendering methods, especially single-page applications based on frameworks such as React and Vue. These applications package various modules and components into packages using packaging tools such as webpack. Static resource files are ultimately run in the browser. However, sometimes we need to run source code or HTML files on the Node.js server for the convenience of development, testing, or operations teams. This article will dive into how to run HTML files in a Node.js environment. 1. Use Exp

May 28, 2023 am 11:47 AM