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High Order Functions in Javascript A function that returns a function or receives a function is called a Higher-Order Function const sayHello = function() { return function() { console.log("Hello!"); } } const myFunc = sayHello(); myFunc();
First-class Functions in Javascript Introduction First-class functions mean functions are treated like any other variable or value A programming language is said to have First-class functions when functions in that language are treated like any other variable A function can be passed as an argument to other functions A function…
Express JS Tutorial Introduction Is a framework that can be used with NodeJS You can build a web app and APIs It supports many features as a plugin which makes it easy Is server-side framework const express = require('express'); const app = express(); const port = 3000; app.get('/', (req, res)…
NPM Basic Tutorial Module vs Package The module may have a group of functions and which is stored in a file to import and reuse The package is a directory that contains one or more modules A package contains a package.json file which contains the metadata about the package NPM…
Good Hash algorithms in nodeJS Introduction Hash algorithms are used to protect the password, card, other sensitive information Following are the widely used MD5 SHA-256 Argon2 PBKDF2 scrypt bcrypt MD5: MD5 stands for message digest Rainbow table problem exists Brute force and reverse output is not much more difficult Let's…
NodeJS security practices Use strict mode Do not use loose comparison == Verify types of untrusted data types Use cryptography Add 2-factor methods
Assert module in nodeJS Introduction The assert module provides a set of assertion functions for verifying invariants We will learn the most used assertion functions Common assertion functions assert.deepEqual() assert.equal() assert.notDeepEqual() assert.notEqual() assert.deepEqual() Tests for deep equality between the actual and expected parameters Comparison details Primitive values are compared with…
Events in NodeJS Introduction Node.js is an asynchronous event-driven architecture All objects that emit events are instances of the EventEmitter class Event names are camel-cased strings When the EventEmitter object emits an event, functions attached to that specific event are called synchronously Implement event eventEmitter.on() method is used to register…
Process object in nodeJS Introduction It is a global object It provides information about and control over the current NodeJS process It is always available to Node.js applications without using require() because its a global object Process events The process object is an instance of EventEmitter beforeExit disconnect exit message…
Global Objects in nodeJS Basics Global Objects These objects are available in all modules The following variables may appear to be global but are not They exist only in the scope of modules __dirname __filename exports module require()