# TrueClass/FalseClass vs. Boolean **URL:** \ **Category:** Ruby\ **Created:** [March 30, 2006, 11:31pm UTC](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403 "2006-03-30T23:31:06Z")\ **Posts on this page:** 4\ **Page:** 2
**Author:** ![PrimaryKey](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/b5ac83/32.png) [@PrimaryKey](https://www.ruby-forum.com/u/PrimaryKey)\ **Post date:** [April 1, 2006, 5:05pm UTC](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403/21 "2006-04-01T17:05:15Z")
On Sat, 1 Apr 2006, Niklas Frykholm wrote: > or this > > while maybe > print “hello” > end in a conditional it should evaluate to true/false radomly - compute a random number and look at the last bit for instance, 0 -\> false, 1 -\> true. harp:~ \> cat a.rb def maybe() [rand].pack(‘f’).unpack(‘c’).first[0].zero? end puts “hello” while maybe harp:~ \> ruby a.rb hello hello harp:~ \> ruby a.rb hello hello hello hello harp:~ \> ruby a.rb hello harp:~ \> ruby a.rb hello cheers. -a ---
**Author:** ![PrimaryKey](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/b5ac83/32.png) [@PrimaryKey](https://www.ruby-forum.com/u/PrimaryKey)\ **Post date:** [January 19, 2007, 9:20pm UTC](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403/22 "2007-01-19T21:20:57Z")
On 3/31/06, removed\_email\_address@domain.invalid [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On Mar 31, 2006, at 5:00 PM, Florian F. wrote: > > > Or just use the literal constants, that already exist: > > case y > > when Integer > > when true, false > > end > > Another example where the Ruby ‘does the right thing’. > Thanks for the reminder. Another, related issue, is the lack of the \<=\> operator for either class. This comes in handy when sorting arrays of booleans or using sort\_by on a collection returned from activerecord that has a boolean attribute. I know this has been covered in the archives of this list before, but I wasn’t able to find any definitive answer from Matz or someone else. I thought it might be because in math Boolean is not really a scalar or a quantifiable value. Or in sortable collection terms, it doesn’t implement Comparable. Other languages work with sorting on booleans because they might bind false to 0 and true to \> 0. So easily fixed by the to\_i above. But in terms of Ruby “doing the right thing”, you’d expect [false, true, false].sort → [false, false, true] because it does this just about everywhere else. This is such a common idiom in CS, that I think Ruby should implement it. But then, I only have just the 2 cents. Anyone know the main reason it does not? Ed ---
**Author:** ![PrimaryKey](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/b5ac83/32.png) [@PrimaryKey](https://www.ruby-forum.com/u/PrimaryKey)\ **Post date:** [January 19, 2007, 10:05pm UTC](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403/23 "2007-01-19T22:05:03Z")
On Jan 19, 2007, at 3:20 PM, Ed Howland wrote: > But in terms of Ruby “doing the right thing”, you’d expect > [false, true, false].sort > –\> [false, false, true] > because it does this just about everywhere else. This is such a common > idiom in CS, that I think Ruby should implement it. But then, I only > have just the 2 cents. Anyone know the main reason it does not? interesting observation Since true and false are not instances of the same class it is like asking how to compare 4 and :foobar or 6.32 and “tuesday”. One possibility would be to have \<=\> be defined in terms of object\_id by default similar to how == is defined. Since false.object\_id is 0 and true.object\_id is 2 that does give you [false,false,true] in your example but for an obscure, implementation dependent reason. Gary W. ---
**Author:** ![PrimaryKey](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/p/b5ac83/32.png) [@PrimaryKey](https://www.ruby-forum.com/u/PrimaryKey)\ **Post date:** [January 19, 2007, 10:27pm UTC](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403/24 "2007-01-19T22:27:09Z")
Ed Howland wrote: > Another, related issue, is the lack of the \<=\> operator for either > class. This comes in handy when sorting arrays of booleans or using > sort\_by on a collection returned from activerecord that has a boolean > attribute. > > I know this has been covered in the archives of this list before, but > I wasn’t able to find any definitive answer from Matz or someone else. The reason, IIRC, was the lack of meaning for true \> false, false \> true, etc. -Justin [Previous page](https://www.ruby-forum.com/t/trueclass-falseclass-vs-boolean/56403.md?page=1)