How to URL Decode a String in Ruby

Introduction

URL decoding, also known as percent decoding, is a method used to safely interpret data in a URL by converting percent-encoded values back into their original reserved and special characters. In Ruby, you can perform URL decoding using the built-in URI module, which offers the decode method for this purpose.

URL Decoding in Ruby

To decode a URL-encoded string in Ruby using the URI module, follow these steps:

require 'uri'

# URL-encoded string
encoded_string = "Hello,%20World!%20How%20are%20you%3F"

# URL decoding
decoded_string = URI.decode(encoded_string)

puts "Encoded String: #{encoded_string}"
puts "Decoded String: #{decoded_string}"

Explanation

1. Begin by importing the URI module with require 'uri'. This module includes the decode method, essential for URL decoding.

2. Define your URL-encoded string that you wish to decode.

3. Apply the URI.decode method to decode the URL-encoded string. This function transforms percent-encoded values back into their original reserved and special characters.

4. Display both the encoded and decoded strings for verification.

Example Output

Encoded String: Hello,%20World!%20How%20are%20you%3F
Decoded String: Hello, World! How are you?

In the output, you can observe that %20 has been decoded into spaces, and %3F has been decoded into a question mark ?. This ensures that the URL-encoded string is correctly interpreted, allowing you to work with the original data in a URL for various applications and web requests.