# A == nil or a.nil? **URL:** \ **Category:** Ruby\ **Created:** [November 23, 2005, 12:05am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976 "2005-11-23T00:05:16Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 12:05am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/1 "2005-11-23T00:05:16Z")
hello, this is more of a philosophical question. my C experience makes me feel more comfortable with expressions such as ‘a == nil’ rather than a.nil?. i feel strange when i invoke a method on a nil value. i know, nil is also an object and not just a zero reference but still it feels strange… would the experts please comment on why one way would be preferable over the other? also, i am curious to know why nil? has been implemented at all? is ‘== nil’ not enough? thanks konstantin ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 12:17am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/2 "2005-11-23T00:17:21Z")
On 11/23/05, ako… [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > over the other? also, i am curious to know why nil? has been > implemented at all? is ‘== nil’ not enough? > > thanks > konstantin for readability, I wager. ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 12:21am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/3 "2005-11-23T00:21:23Z")
On 11/22/05, ako… [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > implemented at all? is ‘== nil’ not enough? > > thanks > konstantin == is usually meant to query whether the data in the objects are the same (or they are the same object). For most == methods, if the data is not comparable (not the same class), it will return false rather than raise an exception. So… == nil should work fine in most cases. I would use one of these which are more direct: a.nil? nil==a # uses the NilClass#== rather than an arbitrary == a.equal?(a) nil.equal?(a) ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 3:26am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/4 "2005-11-23T03:26:33Z")
ako… a écrit : > implemented at all? is ‘== nil’ not enough? > > thanks > konstantin By the way, a == nil is also a method call. It is actually equivalent to: a.==(nil) If nil has a == method, why not adding some other practical methods like nil? ? Actually, nil? is probably a bit faster than ==(nil). – Lionel T. Personal web site: [http://users.skynet.be/lthiry/](http://users.skynet.be/lthiry/) ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 1:29am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/5 "2005-11-23T01:29:47Z")
From: “ako…” [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > this is more of a philosophical question. my C experience makes me feel > more comfortable with expressions such as ‘a == nil’ rather than > a.nil?. i feel strange when i invoke a method on a nil value. Another thing that would be strange in C is: 5.times {print “Hello!”} 🙂 But to me, it’s not worth embracing C’s ideosyncracies when programming in Ruby. The “everything is an object” consistency of Ruby is an elegant and enjoyable part of the language. As an aside, if you’re coming from C, you might be surprised that: a = 0 # zero print “it’s true!” if a # =\> prints “it’s true!” Zero is not false in Ruby. Regards, Bill ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 3:38am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/6 "2005-11-23T03:38:37Z")
On 11/22/05, ako… [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > this is more of a philosophical question. my C experience makes me feel > more comfortable with expressions such as ‘a == nil’ rather than > a.nil?. i feel strange when i invoke a method on a nil value. i know, > nil is also an object and not just a zero reference but still it feels > strange… If you’re not feeling the nil methods, remember nil is the only Boolean false (besides FalseClass). So, unless you specifically need to differentiate between false and nil, you can do this: if !a #stuff end That’s something I see a lot in C, as NULL == false. You might feel more at home, and save a method call. ---
**Author:** ![akonsu](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/13edae/32.png) [@akonsu](https://www.ruby-forum.com/u/akonsu)\ **Post date:** [November 23, 2005, 6:07am UTC](https://www.ruby-forum.com/t/a-nil-or-a-nil/99976/7 "2005-11-23T06:07:27Z")
2005/11/23, Rob R. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid): > if !a > #stuff > end unless a # stuff end