Uses Reverse

Reverse String
Reverse String in Crystal 
module ReverseString
  def self.reverse(input : String) : String
    input.reverse
  end
end

This is the simplest and most exemplary solution, using the built-in String#reverse method. Internally, it uses a very optimized implementation, using a buffer and working directly on the string's bytes. If curious, check the source code.

11th Dec 2024 · Found it useful?

Other Approaches to Reverse String in Crystal

Other ways our community solved this exercise
def self.reverse(input : String) : String
  result = Array(String).new(input.size)
  input.each_char do |char|
    result.unshift(char)
  end
  result.join
end
Use an array

Use an array to store the values. 

def self.reverse(input : String) : String
  result = String.build(input.size) do |builder|
    (0...input.size).reverse_each do |i|
      builder << input[i]
    end
  end
end
Uses String::Builder

Uses String::Builder to build the string.