What is the difference between puts vs return when defining a method?

I struggled with that in the beginning as well. When you're typing the values into IRB or a console, the return and the puts or even print methods look like they do the same thing because all of them appear to be output into a readable format. But they are very different in nature.

Lets say you had a method that added two strings together. Call it anything, but I'll call it "addstring". Code it like this: <br>

def addstring(x,y)
  z = x + y
  return z
end

<br> Then make another method to add two strings. i'll call it "putstring" and code it like this:

def putstring(x,y)
  z = x + y
  puts z
end

Now lets say we want to make a sentence "Have Fun Today" and we want to add it one word at a time (because nothing is going to be easy) and we want to store the value in variable 'words'. We need to use the above functions to make it. The first function "addstring" could be used like this:

  words = addstring(addstring("Have ","Fun "),"Today") 

Calling the variable will return "Have Fun Today"... So it works and that's great. Now lets do that with putstring

 words = putstring(putstring("Have ","Fun "),"Today")

This function will fail miserably and produce a "NoMethodError" with the warning "undefined method for + in NilClass".

This happens because a return value is something that is "returned" from a function, and as a result, it can be stored into an object and used (or reused) in a function. puts on the other hand will return NOTHING but it will 'print' the value to the screen. As a result, puts will not be stored and will, in fact, return a nil value.

Long story short (too late), return gives you the ability to reuse values in other functions, while puts will merely print it to the screen. Definitely try these methods yourself in IRB and attempt to store 'puts' values into variables. You'll see the different responses and get a better idea on how these methods work.

Hope that helps!

puts prints whatever is after it and THEN RETURNS 'NIL'.

'return', on its own, returns 'nil'. However, you can put something after return.

A few examples methods, showing what they return when called:

def method1
        return
        array = []
end

def method2
        array=[]
end

def method3
        array=[]
        return
end

def method4
        puts "Hello"
end

def method5
        x = 2
        something_random = "something_random"
end

def method6
        x = 2
        something_random = "something random"
        return x
end

method1()
=> nil

method2()
=> []

method3()
=> nil

method4()
Hello
=> nil

method5()
=> "something random"

method6()
=> 2

Remember, it's important to play around in irb to experiment.