How to get the returned value from a method from within the method?

Question

I've been practicing some algorithms with ruby for a while, and I'm wondering if it is possible to catch the returned value from within the method.

the code below is to reverse a string without any kind of reverse method and with few local variables...

def rev(a)
 i = -1
 a.split("").each do |el|
  el[0] = a[i]
  i = i + (-1)
 end.join
end

Note that the result of the 'each' method is not being assigned to any variable. So, 'each' evaluates to an array with a reversed sequence of characters. At the 'end' (literally) I've just 'called' the method 'join' to glue everything together. The idea is to 'catch' the returned value from all this process and check if is true or false that the reversed string is a palindrome.

If the reversed string is equal to the original one then the word is a palindrome. Ex. "abba", "sexes", "radar"...

for example:

def rev(a)
 i = -1
 a.split("").each do |el|
  el[0] = a[i]
  i = i + (-1)
 end.join
 # catch here the returned value from the code above
 # and check if its a palindrome or not. (true or false)
end

Thank you guys! I will be very grateful if anyone could help me figure out this!

Answer 1

Just add == a to see if your reversal matches the original string:

def rev(a)
 i = -1
 a.split("").each do |el|
  el[0] = a[i]
  i = i + (-1)
 end.join == a
end

puts rev("racecar") # => true
puts rev("racecars") # => false

An easier way to check palindromes (rev could be better named palindrome?) is a == a.reverse since .reverse is essentially what your split/each/join does.