How To Lowercase A String In Ruby

Lowercasing a string is a common operation in programming. It’s useful when you want to normalize data and remove case sensitivity for things like string comparisons or search operations. Ruby, being a powerful and expressive language, provides a simple method to convert a string to lowercase. In this post, we’ll show you how to lowercase a string in Ruby using the downcase method.

Using the downcase method

The downcase method is a built-in Ruby string method that returns a new string with all uppercase characters converted to their lowercase counterparts. It’s very simple to use, and you can call this method on any string object.

Here’s an example of how to use the downcase method:

original_string = "Convert Me To Lowercase!"
lowercase_string = original_string.downcase

puts lowercase_string
# Output: "convert me to lowercase!"

As you can see, the downcase method creates a new string with all the uppercase characters converted to lowercase. The original string remains unchanged.

Using the downcase! method

If you want to modify the original string directly and convert it to lowercase, you can use the downcase! method. This method is similar to the downcase method, but instead of returning a new string, it modifies the original string in-place.

Here’s an example of how to use the downcase! method:

original_string = "Modify Me In-Place!"


puts original_string
# Output: "modify me in-place!"

The downcase! method updates the original string directly, so be aware of this side effect when using it in your Ruby code.


Lowercasing a string in Ruby is easy and straightforward, thanks to the built-in downcase and downcase! methods. These methods make it simple to normalize and manipulate strings in your Ruby programs.

We hope this guide has helped you understand how to lowercase a string in Ruby. Now go forth and continue mastering the Ruby language!