From: Jian Lin <blueskybreeze@...>
Date: 2010-05-20T05:54:04+09:00
Subject: Re: How to print out all of an object's instance variables?

Dhruva Sagar wrote:
> require 'pp'
> pp object_reference


hm, looks like inspect() by default will print out all the instance 
variables...

but what if not using inspect()?  such as wanting to print them out in a 
table format, between <td> and </td> tags?

require 'pp' works until inspect is redefined, then it will stop working 
and give the following error.  thanks for giving out starting pointers 
though.

irb(main):009:0> class Point
irb(main):010:1>   def initialize(x,y)
irb(main):011:2>     @x,@y = x,y
irb(main):012:2>     @something = 1
irb(main):013:2>   end
irb(main):014:1> end
=> nil
irb(main):015:0> p = Point.new(1,2)
=> #<Point:0x253f260 @y=2, @x=1, @something=1>

irb(main):016:0> p p
#<Point:0x253f260 @y=2, @x=1, @something=1>
=> nil

irb(main):017:0> class Point
irb(main):018:1>   def inspect
irb(main):019:2>     p @x, @y
irb(main):020:2>   end
irb(main):021:1> end
=> nil
irb(main):022:0> p
1
2
=>
irb(main):023:0> p p
1
2

=> nil
irb(main):024:0> require 'pp'
=> true
irb(main):025:0> pp p
1
2
NoMethodError: undefined method `length' for nil:NilClass
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:144:in `text'
        from c:/Ruby/lib/ruby/1.8/pp.rb:259:in `pretty_print'
        from c:/Ruby/lib/ruby/1.8/pp.rb:140:in `pp'
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:201:in `group'
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:227:in `nest'
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:200:in `group'
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:212:in `group_sub'
        from c:/Ruby/lib/ruby/1.8/prettyprint.rb:199:in `group'
        from c:/Ruby/lib/ruby/1.8/pp.rb:140:in `pp'
        from c:/Ruby/lib/ruby/1.8/pp.rb:77:in `pp'
        from c:/Ruby/lib/ruby/1.8/pp.rb:119:in `guard_inspect_key'
        from c:/Ruby/lib/ruby/1.8/pp.rb:77:in `pp'
        from c:/Ruby/lib/ruby/1.8/pp.rb:60:in `pp'
        from c:/Ruby/lib/ruby/1.8/pp.rb:59:in `each'
        from c:/Ruby/lib/ruby/1.8/pp.rb:59:in `pp'
        from (irb):25
irb(main):026:0>


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