res.send() and res.json() Functions in Express.js

Introduction to Sending Response in Express

Express is a popular web application framework that can handle incoming HTTP requests and send responses back to the client. It can be used to send a variety of data types such as plain text, HTML, binary data, or JSON. We can send plain text responses as well as JSON responses.

There are many other methods for sending responses in the express. It depends on the type of data we need to send. res.send() can be used to send the responses with different parameters. There are various parameters used for responses such as HTML, some custom status codes, file path, and header. By analyzing the types of data we can build powerful web applications that can handle various use cases.

Sending Response in Express

In express, there are two types of responses: res.send and res.json. Both of the responses are used for different types of data. So let’s discuss res.send and res.json with examples.

res.send

Syntax

res.send is used to send the HTTP response. As we have already mentioned, there can be different types of parameterized responses. Body parameters can be a string, object, or array. It returns an object to the client.

Example

Output

After running the above code, the following output will be generated:

In the above example, we have required express to use in our web application. urlencoded function is used to parse the incoming requests with urlencoded payloads and it is based on the body parser. we have defined a route for the root path ('/'). When a GET request is made to this route, the route handler function is called with two arguments: req( the request object) and res( the response object).

res.json

Let’s suppose we want to send multiple files, then we will use the res.json() function.

Syntax

Example

Output

After running the above code, the following output will be generated:

In the above example, we are defining a route for '/users'. When a GET request is made to this route, an array is created which consists of user objects, and the res.json() method will be used to send it back to the client as json.