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module.exports vs exports in Node.js
In Node.js, both module.exports and exports are used to define the exports of a module, but there are differences in how they can be used. module.exports module.exports is the actual object that is...
How Do I Convert an Existing Callback API to Promises?
Converting an existing callback-based API to use promises in JavaScript involves wrapping the asynchronous functions with a Promise. Here's a step-by-step guide: Let's assume you have an existing c...
Call async/await Functions in Parallel
To call async/await functions in parallel in JavaScript, you can use Promise.all to concurrently execute multiple asynchronous functions and wait for all of them to complete. Here's an example: // ...
How Can I Print a Circular Structure in a Json-like Format?
If you have an object with circular references in Node.js and you want to print it in a JSON-like format, you can use the util.inspect method from the built-in util module. The util.inspect method ...
How to Read Package Version in node.js Code?
To read the package version in Node.js code, you can use the require function to import the package.json file and access the version property. Here's an example: Assuming your project structure loo...
How to Run Multiple Npm Scripts in Parallel?
To run multiple npm scripts in parallel, you can use a task runner like concurrently or npm-run-all. These tools allow you to execute multiple commands concurrently, making it easy to run multiple ...
How to Access POST Form Fields in Express
In Express.js, you can access POST form fields using the req.body object. To do this, you need to use a middleware called body-parser (for Express versions 4.16.0 and below) or the built-in express...
Node.js: Printing to Console without a Trailing Newline?
In Node.js, you can print to the console without a trailing newline by using the process.stdout.write() method. Unlike console.log(), which automatically adds a newline character (\\n) at the end, ...
Why Does "npm install" Rewrite package-lock.json?
When you run the command npm install, npm installs the dependencies specified in your package.json file and generates or updates the package-lock.json file. The package-lock.json file is used to pr...
How to Check if a Tag Exists in Logstash?
To determine whether a tag exists within Logstash, you can use conditional statements. Here's how you can do that: if "yourtag" in [tags] { # Perform actions when the tag "yourtag" exists } This...
How to Use JSON with Logstash?
If you have JSON-formatted logs that you want to ingest and process with Logstash, follow these steps: Assuming you have logs in the following JSON format: {"status": 200, "ip": "127.0.0.1", "level...
How to Check if a Field Exists in Logstash
If you need to determine whether a field like your_field exists in your Logstash data, you can use conditional statements. The steps to achieve this are below. For numerical types, you can use the ...
How to Force Logstash to Reparse a File?
By default, Logstash's file input plugin tracks the parts of a file it has already processed. However, when you want Logstash to reparse a file starting from the beginning, you would need to set th...
Why does "npm install" rewrite package-lock.json?
When you run the command npm install, npm installs the dependencies specified in your package.json file and generates or updates the package-lock.json file. The package-lock.json file is used to pr...
How to change node.js's console font color?
In Node.js, you can change the console font color by using ANSI escape codes. ANSI escape codes are sequences of characters that control text formatting, including colors. Here's a simple example o...
How to list npm user-installed packages?
To list npm user-installed packages, you can use the npm list command in the terminal. By default, this command will show a tree-like structure of all installed packages for the current project. If...
How to Upgrade Node.js to the Latest Version on Mac OS?
To upgrade Node.js to the latest version on macOS, you can use a version manager like nvm (Node Version Manager) or directly download and install the latest Node.js version from the official websit...
How is an HTTP POST request made in node.js?
In Node.js, you can make an HTTP POST request using the http or https modules that come with Node.js, or you can use a more user-friendly library like axios or node-fetch. Here, I'll provide exampl...
How to create a directory if it doesn't exist using Node.js
In Node.js, you can use the fs (file system) module to create a directory if it doesn't exist. The fs module provides the mkdir function for creating directories. Here's an example: const fs = requ...
Error: Can't set headers after they are sent to the client
The "Error: Can't set headers after they are sent to the client" error typically occurs in Node.js when you attempt to set HTTP headers (e.g., using res.setHeader() or res.writeHead()) after the re...
How to install a previous exact version of a NPM package?
To install a specific version of an npm package, you can use the npm install command along with the package name and the desired version number. Here's the syntax: npm install @ Replace with the n...
In Node.js, how do I "include" functions from my other files?
In Node.js, you can include (import) functions from other files using the require statement. Here's an example of how to include functions from another file: Suppose you have a file named mathFunct...
How can I do Base64 encoding in Node.js?
In Node.js, you can use the built-in Buffer class to perform Base64 encoding and decoding. The Buffer class provides methods for encoding and decoding data in various formats, including Base64. Her...
Using Node.js as a simple web server
Node.js comes with a built-in module called http that can be used to create a simple web server. Below is a basic example of how to create a simple HTTP server using Node.js: const http = require('...
Using Node.js require vs. ES6 import/export
Node.js uses CommonJS-style require for module loading, while ES6 introduces a native import and export syntax. Each has its own style and use cases. Using require (CommonJS): // Importing a module...
How do I get the path to the current script with Node.js?
In Node.js, you can use the __filename variable to get the absolute path to the current script file, and __dirname to get the absolute path to the directory containing the current script. Here's an...
How can I uninstall npm modules in Node.js?
To uninstall npm modules (packages) in Node.js, you can use the npm uninstall command followed by the name of the module you want to remove. Here are a few examples: Uninstalling a Local Module: To...
How can I get the full object in Node.js's console.log(), rather than '[Object]'?
By default, console.log() in Node.js will display [Object] when trying to log an object. If you want to see the full contents of an object, you can use util.inspect() from the util module, which is...
How to reduce size of node_modules folder?
Reducing the size of the node_modules folder in a Node.js project can be important, especially when deploying applications or managing version control. Here are several strategies you can use to mi...
How to check synchronously if file/directory exists in Node.js?
In Node.js, you can use the fs (file system) module to check synchronously if a file or directory exists. The fs.existsSync() function can be used for this purpose. Here's an example: const fs = re...
How to fix npm throwing error without sudo?
If you are encountering errors when trying to run npm without using sudo, it's likely related to permission issues. Running npm with sudo can lead to problems with file ownership and permissions, a...
How to read environment variables in Node.js
In Node.js, you can read environmental variables using the process.env object. This object provides access to the user environment, including environment variables. Here's a simple example of how y...
How to use multiple node versions on the same machine?
There are several ways to manage multiple Node.js versions on the same machine. Here are two popular tools for achieving this: NVM (Node Version Manager): NVM is a widely used tool for managing mul...
What is the purpose of Node.js module.exports and how do you use it?
In Node.js, module.exports is a special object that is used to define what a module exports as its public interface. It is used to expose functionality from one module (file) to another module, all...
How to get `GET` variables in Express.js on Node.js?
In Express.js, you can access GET (query string) variables using the req.query object. The req.query object contains key-value pairs of the query string parameters in a GET request. Here's an examp...
How do you get a list of the names of all files present in a directory in Node.js?
In Node.js, you can use the fs (file system) module to get a list of file names in a directory. Here's an example using the fs.readdir function: const fs = require('fs'); const directoryPath = '/pa...
How do I debug Node.js applications?
Debugging Node.js applications can be done using various tools and techniques. Here are some common approaches to debug Node.js applications: console.log The simplest form of debugging is using con...
Is there a map function for objects in Node.js?
In JavaScript, the map function is typically used with arrays to transform each element of the array based on a provided callback function. If you want to achieve a similar result with objects, you...
How to write to files in Node.js?
In Node.js, you can use the fs (file system) module to read from and write to files. Here's a basic example of how to write and read files in Node.js using callbacks: const fs = require('fs'); // W...
How can I update Node.js and NPM to their latest versions?
There are several ways to update Node.js to its latest version. Here are three methods: Updating Node.js Using NPM You can use NPM to update Node.js by installing the n package, which will be used ...
How to decide when to use Node.js?
Node.js is a powerful, JavaScript-based runtime environment that has shaped the modern web landscape, enabling developers to build fast, scalable, and efficient web applications. To Node.js or not ...
How to exit in Node.js
Exiting a Node.js application is simple and can be done using the process.exit() method. This method exits from the current Node.js process and takes an exit code, which is an integer. The exit cod...
How can I update each dependency in package.json to the latest version?
To update each dependency in package.json to the latest version, you can use the npm-check-updates package. Here are the steps: Install the npm-check-updates package globally by running the followi...
What's the difference between dependencies, devDependencies, and peerDependencies in NPM package.json file?
When you create a new Node.js project, you’ll notice a package.json file in the root directory. This file contains metadata about your project, including the dependencies required to run ...
How to find the version of an installed npm package?
To find the version of an installed npm package, you can use the following commands: To see the version of an installed Node.js or npm package, run npm list . To see the latest version of a pa...
How do I pass command line arguments to a Node.js program and receive them?
In Node.js, you can pass command line arguments to your script the same as you would for any other command line application. Simply type your arguments after the script path separated with a space ...
What is the --save option for npm install?
The --save option for npm install was once used to add the installed module into the dependencies section of your package.json file automatically. However, from npm version 5.0.0 this is no longer...
Using async/await with a forEach loop?
In Node.js, the forEach loop is not compatible with the async/await syntax as it does not wait for promises. But fear not, as there are two alternatives: The for(… of …) loop If you would like to h...
What’s the Difference between Tilde(~) and Caret(^) in package.json?
In a package.json file, the tilde (~) and caret (^) symbols are used to specify version ranges for your project’s dependencies. They help you control which versions of packages can your p...
How to Read Textbox Values in Playwright Tests
To read textbox values in Playwright, you can use the inputValue() method on a locator pointing to the textbox. Here's a step-by-step guide:
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