I can't get hash list params working

ruby-talk
1

Hi

I must be doing something stoopid here. Can anyone explain why I get an error on the last line of this irb session?

irb(main):014:0> def a(a=nil,*b)
irb(main):015:1> puts a.inspect
irb(main):016:1> puts b.inspect
irb(main):017:1> end
=> nil
irb(main):018:0> a(1 => "one", 2 => "two")
{1=>"one", 2=>"two"}
[]
=> nil
irb(main):019:0> a(1 => "one", 2 => "two", 1)
SyntaxError: compile error
(irb):19: parse error, unexpected ')', expecting tASSOC
         from (irb):19

Surely the output should be
   {1=>"one", 2=>"two"}
   [1]
?

I tried the example in Pickaxe v2 (p349) and got a similar error. Someone please slap my head for me :slight_smile:

thanks
Ashley

···

from :0

2

Hi --

···

On Sun, 2 Apr 2006, Ashley Moran wrote:

Hi

I must be doing something stoopid here. Can anyone explain why I get an error on the last line of this irb session?

irb(main):014:0> def a(a=nil,*b)
irb(main):015:1> puts a.inspect
irb(main):016:1> puts b.inspect
irb(main):017:1> end
=> nil
irb(main):018:0> a(1 => "one", 2 => "two")
{1=>"one", 2=>"two"}

=> nil
irb(main):019:0> a(1 => "one", 2 => "two", 1)
SyntaxError: compile error
(irb):19: parse error, unexpected ')', expecting tASSOC
      from (irb):19
      from :0

Surely the output should be
{1=>"one", 2=>"two"}
[1]
?

You can only use the "magic" hash argument if it's the last thing in
the arglist. If it isn't, you have to write it like a regular hash:

   a({1 => "one", 2 => "two"}, 1)

David

--
David A. Black (dblack@wobblini.net)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)

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