Node.js Query Strings

Introduction to Query Strings

Query strings are a part of a URL that comes after the question mark (?). They are composed of key-value pairs separated by an ampersand (&). In Node.js, query strings can be parsed and manipulated using the querystring module.

The querystring module provides utilities for parsing and formatting URL query strings. Although it's often used for simple operations, it is important to understand how to use it effectively in your Node.js applications.

Using the querystring Module

To use the querystring module in your Node.js application, you first need to require it. Here is a basic example of how to parse a query string:

The code above will output:

The querystring.parse() method converts a query string into a JavaScript object. This allows you to easily access each parameter by its name.

Formatting Query Strings

In addition to parsing, the querystring module can also format an object into a query string using the querystring.stringify() method. Here's how to do it:

The code above will output:

The querystring.stringify() method is useful for constructing a query string from an object, which can then be appended to a URL.

Handling Special Characters

When dealing with query strings, special characters in parameter values are percent-encoded. The querystring module provides methods to handle encoding and decoding:

This code decodes the percent-encoded string into a readable format. Encoding and decoding ensure that special characters do not interfere with the query string.