I was going through the exercises in Ruby Koans and I was struck by the following Ruby quirk that I found really unexplainable:
array = [:peanut, :butter, :and, :jelly]
array[0] #=> :peanut #OK!
array[0,1] #=> [:peanut] #OK!
array[0,2] #=> [:peanut, :butter] #OK!
array[0,0] #=> [] #OK!
array[2] #=> :and #OK!
array[2,2] #=> [:and, :jelly] #OK!
array[2,20] #=> [:and, :jelly] #OK!
array[4] #=> nil #OK!
array[4,0] #=> [] #HUH?? Why's that?
array[4,100] #=> [] #Still HUH, but consistent with previous one
array[5] #=> nil #consistent with array[4] #=> nil
array[5,0] #=> nil #WOW. Now I don't understand anything anymore...
So why is array[5,0] not equal to array[4,0]? Is there any reason why array slicing behaves this weird when you start at the (length+1)th position??