String#reverse

str.reverse -> string

Returns: String · Updated March 13, 2026 · String Methods

strings manipulation reverse

String#reverse returns a new string with the characters in reverse order. It does not modify the original string, making it safe to use without worrying about unintended side effects. This method is particularly useful for palindrome checking, text processing, and any scenario where you need to flip the character order of a string. The method has been part of Ruby’s standard library since version 1.8 and works consistently across all Ruby implementations including MRI, JRuby, and Rubinius.

Syntax

string.reverse

Parameters

This method takes no parameters and requires no arguments. The method operates entirely on the string it is called on.

Examples

Basic usage

"hello".reverse
# => "olleh"

"Ruby".reverse
# => "ybuR"

"".reverse
# => ""

Reversing a palindrome

"racecar".reverse
# => "racecar"

"madam".reverse
# => "madam"

Reversing words in a sentence

"hello world".reverse
# => "dlrow olleh"

Common Patterns

Checking if a string is a palindrome

def palindrome?(word)
  word == word.reverse
end

palindrome?("racecar")  # => true
palindrome?("hello")   # => false

Working with multibyte characters

# Works with any string encoding
"Japanese".reverse
# => "esepaJ"

# Handles multibyte characters correctly
"cafe".reverse
# => "efac"

Reversing for coding challenges

# Common interview question: reverse words in a string
def reverse_words(str)
  str.split(" ").reverse.join(" ")
end

reverse_words("hello world")
# => "world hello"

Errors

String#reverse never raises an error. It works on empty strings and returns an empty string. The method is completely safe and has no edge cases that would cause exceptions.