Found 70 Questions for Express JS

Using next() function in Express.js

Mayank Agarwal
Updated on 01-Oct-2021 06:54:31
Express.js is a powerful tool for building web servers to hit API at backend. It has several advantages which makes it popular, however it has got some drawbacks too, for example, one needs to define different routes or middleware to handle different incoming requests from the client.In this article, we will see how to use the next() function in a middleware of Express.js. There are lots of middleware in Express.js. We will use the app.use() middleware to define the handler of the particular request made by client.Syntaxapp.use(path, (req, res, next) )Parameterspath – This is the path for which the middleware ... Read More

Express.js – express.text() function

Mayank Agarwal
Updated on 01-Oct-2021 06:44:18
express.text() is a built-in middleware function in Express. It parses the incoming request payloads into a string and it is based upon the body-parser. This method returns the middleware that parses all the bodies as strings.Syntaxexpress.text([options])ParametersFollowing are the different options available with this methodoptionsinflate – It enables or disables the handling of the deflated or compressed bodies. Default: truelimit – It controls the maximum size of the request body.defaultCharset – This option specifies the default character set for the text content if the charset is not specified in the Content-type header of the request.type – It determines the media type ... Read More

Express.js – express.raw() function

Mayank Agarwal
Updated on 01-Oct-2021 06:37:28
express.raw() is a built-in middleware function in Express. It parses the incoming requests into a buffer and it is based upon the body-parser. This method returns the middleware that parses all JSON bodies as buffer and only looks at the requests where the content-type header matches the type option.Syntaxexpress.raw([options])ParametersFollowing are the different options available with this methodoptions –inflate – This enables or disables the handling of the deflated or compressed bodies. Default: truelimit – Controls the maximum size of the request body.type – Determines the media type for the middleware that will be parsed.Example 1Create a file with the name "expressRaw.js" ... Read More

Express.js – express.json() function

Mayank Agarwal
Updated on 01-Oct-2021 06:32:10
express.json() is a built-in middleware function in Express. This method is used to parse the incoming requests with JSON payloads and is based upon the bodyparser.This method returns the middleware that only parses JSON and only looks at the requests where the content-type header matches the type option.Syntaxexpress.json([options])ParametersFollowing are the different options available with this methodoptionsinflate – This enables or disables the handling of the deflated or compressed bodies. Default: truelimit – This controls the maximum size of the request body.reviver – This option is passed to the JSON.parse method as the second argument.strict – This enables or disables the ... Read More

Express.js – app.use() Method

Mayank Agarwal
Updated on 01-Oct-2021 06:25:03
The app.use() method mounts or puts the specified middleware functions at the specified path. This middleware function will be executed only when the base of the requested path matches the defined path.Syntaxapp.use([path], callback, [callback])Parameterspath − This is the path for which the middleware function is invoked. A path can be a string, path pattern, a regular expression or an array of all these.callback − These are the middleware functions or a series of middleware functions that acts like a middleware except that these callbacks can invoke next (route).Example 1Create a file with the name "appUse.js" and copy the following code ... Read More

Express.js – app.set() Method

Mayank Agarwal
Updated on 30-Sep-2021 14:28:38
The app.set() function assigns or sets a setting name to value. This can store any type of value as the user wants, but there are some certain names that can be used to configure the behaviour of the serverSome of the properties that can be configured with the set functionality are −envetagjsonp escape, etcSyntaxapp.set(name, value)Example 1Create a file with the name "appSet.js" and copy the following code snippet. After creating the file, use the command "node appSet.js" to run this code.// app.set() Demo Example // Importing the express module var express = require('express'); // Initializing the express and ... Read More

Express.js – app.route() Method

Mayank Agarwal
Updated on 30-Sep-2021 14:18:50
The app.route() method returns the instance of a single route. This single route can be used to handle the HTTP verbs with the optional middleware. This method is mainly used to avoid duplicate names.Syntaxapp.route( )Example 1Create a file with the name "appRoute.js" and copy the following code snippet. After creating the file, use the command "node appRoute.js" to run this code.// app.route() Demo Example // Importing the express module var express = require('express'); // Initializing the express and port number var app = express(); var PORT = 3000; // Creating a get, post & other requests app.route('/user') ... Read More

Express.js – app.render() Method

Mayank Agarwal
Updated on 30-Sep-2021 14:04:25
The app.render() method is used for returning the rendered HTML of a view using the callback function. This method accepts an optional parameter that is an object which contains the local variables for the view.This method is similar to the res.render() function with the difference that it cannot send the rendered view to the client/user itself.Syntaxapp.render(view, [locals], callback)ExampleCreate a file with the name "appRender.js" and copy the following code snippet. After creating the file, use the command "node appRender.js" to run this code.// app.render() Method Demo Example // Importing the express module const express = require('express'); // Initializing ... Read More

Express.js – app.post() Method

Mayank Agarwal
Updated on 30-Sep-2021 13:59:08
The app.post() method routes all the HTTP POST requests to the specified path with the specified callback functions.Syntaxapp.path(path, callback, [callback])Parameterspath − This is the path for which the middleware function is invoked. A path can be a string, path pattern, a regular expression or an array of all these.callback − These are the middleware functions or a series of middleware functions that acts like a middleware except that these callbacks can invoke next (route).Example 1Create a file with the name "appPost.js" and copy the following code snippet. After creating the file, use the command "node appPost.js" to run this code.// ... Read More

Express.js – app.path() Method

Mayank Agarwal
Updated on 30-Sep-2021 13:55:55
The app.path() method returns the canonical path. The path is returned as a string. It is better to use the req.baseUrl method since the app.path() method can be very complicated in complex cases of mounted apps.Syntaxapp.path( )Example 1Create a file with the name "appPath.js" and copy the following code snippet. After creating the file, use the command "node appPath.js" to run this code.// app.path() Demo Example // Importing the express module var express = require('express'); // Initializing the express and port number var app = express(); var PORT = 3000; // Assigning express constructor var app = ... Read More
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