From: Edmond Kachale <kachaleedmond@...>
Date: 2010-09-03T19:47:51+09:00
Subject: Re: p vs. print

Let IRB speak for himself:
****
>> x = [2,4,1]
=> [2, 4, 1]
>> p x
[2, 4, 1]
=> nil
>> puts x
2
4
1
=> nil
>> print x
241=> nil
>> p x.inspect
"[2, 4, 1]"
=> nil
>> puts x.inspect
[2, 4, 1]
=> nil
>> print x.inspect
[2, 4, 1]=> nil
>> p x.to_s
"241"
=> nil
>> puts x.to_s
241
=> nil
>> print x.to_s
241=> nil
****

p x = puts x.inspect

ceekays
=======

Brian Candler wrote:
> Abder-Rahman Ali wrote:
>> When I tried to display the result using
>> 
>> print ary1
>> 
>> It did NOT show anything.
> 
> print(x) calls x.to_s to get the string representation, then sends that 
> to $stdout.
> 
> It looks like the object you have returns an empty string or nil from 
> its to_s method (which is odd, but you'd have to talk to the author of 
> the NArray class about that)
> 
> puts(x) is like print(x), but adds a newline if there isn't one at the 
> end of the string already.
> 
> p(x) is like puts(x.inspect), where x converts an object into a 
> debugging string form, that is, one which shows its internal state.
> 
> Try this program to see the differences:
> 
> class Foo
>   def initialize(a)
>     @a = a
>   end
>   def to_s
>     "here's a string"
>   end
> end
> 
> f = Foo.new(123)
> print f
> puts f
> p f

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