Ruby challenge: Reversing Strings by Words

Ruby challenge: Reversing Strings by Words


How to revert a String by words. The letters (or words) of your string are in the wrong order.


Given a String, return a new one in a reversed order by words. As an example, This original string "order correct a not is this " would become "this is not a correct order".


Strings in programming

A string is a data type commonly used in programming languages to represent a sequence of characters. It is used to store and manipulate textual data. In most programming languages, strings are surrounded by quotation marks, such as single quotes ('') or double quotes ("").

Strings can contain letters, numbers, symbols, and special characters. They can represent words, sentences, paragraphs, file paths, URLs, and more.

Strings in Ruby

In Ruby, a string is an object that represents a sequence of characters. It is an instance of the String class, which is part of Ruby's core library. The String class provides a wide range of methods and functionalities for manipulating and working with strings.

In terms of inheritance, the String class is a subclass of the Object class. The Object class is the top-level class in Ruby's object hierarchy, and all classes, including String, ultimately inherit from it.


Let's consider the following string

string = "city the in favorite my is building this"


irb(main):001:0> string = "city the in favorite my is building this"
=> "city the in favorite my is building this"

The proposed solution is

string.split.reverse.join(' ')


irb(main):005:0> string.split.reverse.join(' ')
=> "this building is my favorite in the city"


Separate the words



irb(main):007:0> string.split
=> ["city", "the", "in", "favorite", "my", "is", "building", "this"]

The split method in Ruby is used to divide a string into an array of substrings based on a specified delimiter.

The method takes an optional argument, the delimiter, which determines where the string should be split. If no delimiter is provided, the default delimiter is a whitespace character.

The split method scans the original string and identifies occurrences of the delimiter. Each time the delimiter is found, the string is divided into two parts, and the part before the delimiter is added as an element to the resulting array.

As a result, we have an array of words.

Reverse the words



irb(main):009:0> string.split.reverse
=> ["this", "building", "is", "my", "favorite", "in", "the", "city"]

The reverse method in Ruby is used to reverse the order of:

  • elements in an array; or

  • characters in a string.

It's important to note that the reverse method does not modify the original array or string. Instead, it returns a new object with the reversed order.

Converto into a string

string.split.reverse.join(' ')


irb(main):010:0> string.split.reverse.join(' ')
=> "this building is my favorite in the city"

The join method in Ruby is used to concatenate the elements of:

  • an array, or

  • collection

into a single string.

It takes a separator as an optional argument and returns a new string formed by joining the elements together with the specified separator.

The method iterates through the elements of the array or collection and converts each element to a string.

It then concatenates the elements together, placing the separator between them, and returns the resulting string.

Without arguments

If called without any arguments, the join method concatenates the elements of the array or collection together without any separator. It converts each element to a string and places them side by side.

In our example, the result of


would be

irb(main):011:0> string.split.reverse.join
=> "thisbuildingismyfavoriteinthecity"

With arguments

If called with an argument, the argument specifies the separator that should be inserted between the elements when joining them into a single string.

The separator can be any string or character.

The result of


would be

irb(main):012:0> string.split.reverse.join('#')
=> "this#building#is#my#favorite#in#the#city"


Best Michael Scott Reaction GIFs | Gfycat

Let's become friends

Final thoughts

I hope this article helped you. Let me know if you have any questions.

Your thoughts, suggestions and corrections are more than welcome.

By the way, feel free to drop your suggestions on new blog articles.

Hope to see you next time.