Ruby Programming Language :: Hash behavior query


	Hash behavior query irb(main):001:0> d = [1,2,3,4] => [1, 2, 3, 4] irb(main):002:0> h = Hash.new => {} irb(main):003:0> h[d] = "hello" => "hello" irb(main):004:0> h => {[1, 2, 3, 4]=>"hello"} irb(main):005:0> h[d] => "hello" irb(main):006:0> d.push(5) => [1, 2, 3, 4, 5] irb(main):007:0> h[d] => nil irb(main):008:0> h => {[1, 2, 3, 4, 5]=>"hello"} irb(main):009:0> d => [1, 2, 3, 4, 5] irb(main):010:0> h[d] => nil irb(main):011:0> h.rehash => {[1, 2, 3, 4, 5]=>"hello"} irb(main):012:0> h[d] => "hello" irb(main):013:0> Is this expected or a bug? -abhisek Hi -- - Hide quoted text - On Wed, 30 May 2007, Abhisek Datta wrote: > irb(main):001:0> d = [1,2,3,4] > => [1, 2, 3, 4] > irb(main):002:0> h = Hash.new > => {} > irb(main):003:0> h[d] = "hello" > => "hello" > irb(main):004:0> h > => {[1, 2, 3, 4]=>"hello"} > irb(main):005:0> h[d] > => "hello" > irb(main):006:0> d.push(5) > => [1, 2, 3, 4, 5] > irb(main):007:0> h[d] > => nil > irb(main):008:0> h > => {[1, 2, 3, 4, 5]=>"hello"} > irb(main):009:0> d > => [1, 2, 3, 4, 5] > irb(main):010:0> h[d] > => nil > irb(main):011:0> h.rehash > => {[1, 2, 3, 4, 5]=>"hello"} > irb(main):012:0> h[d] > => "hello" > irb(main):013:0> > Is this expected or a bug? You've pretty much reproduced the documented example from the source code, so I'd say it's expected :-) David -- Q. What is THE Ruby book for Rails developers? A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black) (See what readers are saying! http://www.rubypal.com/r4rrevs.pdf) Q. Where can I get Ruby/Rails on-site training, consulting, coaching? A. Ruby Power and Light, LLC (http://www.rubypal.com) On 5/30/07, dbl@wobblini.net <dbl@wobblini.net> wrote: - Hide quoted text - > Hi -- > On Wed, 30 May 2007, Abhisek Datta wrote: > > irb(main):001:0> d = [1,2,3,4] > > => [1, 2, 3, 4] > > irb(main):002:0> h = Hash.new > > => {} > > irb(main):003:0> h[d] = "hello" > > => "hello" > > irb(main):004:0> h > > => {[1, 2, 3, 4]=>"hello"} > > irb(main):005:0> h[d] > > => "hello" > > irb(main):006:0> d.push(5) > > => [1, 2, 3, 4, 5] > > irb(main):007:0> h[d] > > => nil > > irb(main):008:0> h > > => {[1, 2, 3, 4, 5]=>"hello"} > > irb(main):009:0> d > > => [1, 2, 3, 4, 5] > > irb(main):010:0> h[d] > > => nil > > irb(main):011:0> h.rehash > > => {[1, 2, 3, 4, 5]=>"hello"} > > irb(main):012:0> h[d] > > => "hello" > > irb(main):013:0> > > Is this expected or a bug? > You've pretty much reproduced the documented example from the source > code, so I'd say it's expected :-) .. and furthermore was there not somebody asking whether to prefer Strings or Symbols as hash keys. I think the example above gives you some hints, -- sometimes Strings are still a good choice, but only sometimes. Cheers Robert -- You see things; and you say Why? But I dream things that never were; and I say Why not? -- George Bernard Shaw