Today I looked at: https://ruby-doc.org/core-2.5.1/Array.html#method-i-initialize_copy The example to this method is this: ```ruby a = [ "a", "b", "c", "d", "e" ] a.replace([ "x", "y", "z" ]) #=> ["x", "y", "z"] a #=> ["x", "y", "z"] ``` What confused me was that I was looking at the method called `initialize_copy` initialize_copy but the example showed `.replace()`. .replace(). I then looked at `#replace` #replace there: https://ruby-doc.org/core-2.5.1/Array.html#method-i-replace And it was virtually identical to `initialize_copy`. initialize_copy. I assume the examples for `.replace()` .replace() are correct; and perhaps `initialize_copy` initialize_copy is just an alias? I am not sure, but I would like to suggest to make the documentation, in particular the example, a bit more consistent. When you click on "view source" to look at the C code, they show the very same content, so I believe that initialize_copy is merely an alias to replace; but I tried this and they are not fully equivalent: ```ruby x = [1,2,3] # => [1, 2, 3] x.initialize_copy [4,5,6] ``` ``` Traceback (most recent call last): 2: from /System/Index/bin/irb:11:in `<main>' 1: from (irb):2 NoMethodError (private method `initialize_copy' called for [1, 2, 3]:Array) ``` Yet: ```ruby x.replace [4,5,6] # => [4, 5, 6] ``` works. So I assume that `initialize_copy` initialize_copy is like `.replace()` .replace() but is a private method instead. Perhaps it may help to add a sentence below the documentation of `replace()`, replace(), to explain what the use case for `initialize_copy` initialize_copy is. Or to perhaps mention that it is an alias. At the least how it is right now is that people may read initialize_copy, but then see an example of #replace. (Perhaps an example for initialize_copy may help, but either way, I think the current docu-example is not ideal).