Different between 2 code

[Amir Ebrahimifard]

Hi
Why 2 different sort in below code return different result ?
( I dont understand different between "v1 <=> v2" and "v2 <=> v1" ).

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array = [3,1,5,2,4]
# => [3, 1, 5, 2, 4]

array.sort {|v1,v2| v1 <=> v2 }
# => [1, 2, 3, 4, 5]
array.sort {|v1,v2| v2 <=> v1 }
# => [5, 4, 3, 2, 1]

 

[Bob Smith]

( I dont understand different between "v1 <=> v2" and "v2 <=> v1" ).

I think a quick Google search on the "spaceship operator" should help
you with understanding the differences.

 

[Brian Candler]

Hi
Why 2 different sort in below code return different result ?
( I dont understand different between "v1 <=> v2" and "v2 <=> v1" ).

irb(main):001:0> 1 <=> 2
=> -1
irb(main):002:0> 2 <=> 1
=> 1
irb(main):003:0> 1 < 2
=> true
irb(main):004:0> 2 < 1
=> false