Home » Ruby programming » Ruby programs

Ruby program to reverse a string | Set 2

Ruby | Reversing string: Here, we are going to learn different ways to reverse a string in Ruby programming language.
Submitted by Hrithik Chandra Prasad, on April 10, 2020

Ruby | Reversing string

Here, we are implementing a Ruby program to reverse a string.

Methods used:

• gets: This method is a public instance method of String class which is used to take input from the console.
• puts: This method is a public instance method of String class which is used to print Strings on the console.
• reverse: This method is a public instance method of String class which is used to reverse the String object.
• split: This method is a public instance method of String class which is used to convert the String into array instance.
• length: This method is a public instance method of String class which is used to find the number of characters present in the String.
• times: This is a kind of loop through which the statement iterates for a given number of times.
• push: This method is used to add character to the array object.
• pop: This method is used to remove the character from the array object.
• join: This method is used to covert the Array object into the String.

Example 1: Without using library method reverse

=begin
  Ruby program to reverse a String.		
=end

def rev_str(str)
  s_str = str.split("")
  new_str = []
  str.length.times{new_str.push(s_str.pop)}
  new_str.join
end

puts "Enter the String you want to reverse:"
string = gets.chomp
puts "The reversed String is #{rev_str(string)}"

Output

Enter the String you want to reverse:
 includehelp.com
The reversed String is moc.plehedulcni

Explanation:

In the above code, you can observe that we have defined a function that is responsible for reversing the String object. First, we have converted the String into an Array object then after processing it, we have converted it back to a String object.

Example 2:

=begin
  Ruby program to reverse a String.		
=end

puts "Enter the String you want to reverse:"
string = gets.chomp

rev_string = string.reverse

puts "The reversed String is #{rev_string}"

Output

RUN 1:
Enter the String you want to reverse:
 includehelp.com
The reversed String is moc.plehedulcni

RUN 2:
Enter the String you want to reverse:
 Hello World!
The reversed String is !dlroW olleH

Explanation:

In the above code, you can observe that we have invoked the method reverse which is a public instance method defined in Ruby's library for reversing the String. For creating the permanent changes in the String you can invoke reverse! method.