Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Programming > Ruby > Can anyone give a an example of this please

Reply
Thread Tools

Can anyone give a an example of this please

 
 
Kaye Ng
Guest
Posts: n/a
 
      10-07-2010
"code blocks may accept none, one, or more parameters"

I understand how ONE parameter is passed using the 'each' method.
I also understand how TWO parameters is passed, like in this code
x = { "a" => 100, "b" => 20 }
x.delete_if { |key, value| value < 25 }
p x

Can anyone give me a very simple and executable code where:
NO parameters is passed, and
THREE parameters is passed

SIMPLE CODE/SYNTAX ONLY PLEASE, BEGINNER HERE. =D

Thanks so much.
--
Posted via http://www.ruby-forum.com/.

 
Reply With Quote
 
 
 
 
Phillip Gawlowski
Guest
Posts: n/a
 
      10-07-2010
On Thu, Oct 7, 2010 at 2:01 PM, Kaye Ng <(E-Mail Removed)> wrote:
> "code blocks may accept none, one, or more parameters"
>
> I understand how ONE parameter is passed using the 'each' method.
> I also understand how TWO parameters is passed, like in this code
> x = { "a" => 100, "b" => 20 }
> x.delete_if { |key, value| value < 25 }
> p x
>
> Can anyone give me a very simple and executable code where:
> NO parameters is passed, and


irb(main):001:0> [0,1,2,3].each { puts "no param" }
no param
no param
no param
no param
=> [0, 1, 2, 3]

> THREE parameters is passed


irb(main):002:0> [ [ 1,2,3 ] ].each { |i,j,k| puts i+j+k }
6
=> [[1, 2, 3]]


Ruby version is 1.9.1

> SIMPLE CODE/SYNTAX ONLY PLEASE, BEGINNER HERE. =D


Was this simple enough?

--
Phillip Gawlowski

Though the folk I have met,
(Ah, how soon!) they forget
When I've moved on to some other place,
There may be one or two,
When I've played and passed through,
Who'll remember my song or my face.

 
Reply With Quote
 
 
 
 
Robert Klemme
Guest
Posts: n/a
 
      10-07-2010
On Thu, Oct 7, 2010 at 2:01 PM, Kaye Ng <(E-Mail Removed)> wrote:
> "code blocks may accept none, one, or more parameters"
>
> I understand how ONE parameter is passed using the 'each' method.
> I also understand how TWO parameters is passed, like in this code
> x = { "a" => 100, "b" => 20 }
> x.delete_if { |key, value| value < 25 }
> p x
>
> Can anyone give me a very simple and executable code where:
> NO parameters is passed, and
> THREE parameters is passed


14:14:24 ~$ ruby19 <<CODE
> def none; yield; end
> def one; yield 1; end
> def three; yield 1,2,3; end
> none { puts "called" }
> one {|x| puts "Got one: #{x}"}
> three {|a,b,c| puts "Got three: #{a}, #{b}, #{c}"}
> three {|a| p a}
> three {|*a| p a}
> CODE

called
Got one: 1
Got three: 1, 2, 3
1
[1, 2, 3]
14:15:44 ~$

> SIMPLE CODE/SYNTAX ONLY PLEASE, BEGINNER HERE. =D


Please do not shout.

robert

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

 
Reply With Quote
 
Robert Klemme
Guest
Posts: n/a
 
      10-07-2010
On Thu, Oct 7, 2010 at 2:14 PM, Phillip Gawlowski
<(E-Mail Removed)> wrote:
> On Thu, Oct 7, 2010 at 2:01 PM, Kaye Ng <(E-Mail Removed)> wrote:
>> "code blocks may accept none, one, or more parameters"
>>
>> I understand how ONE parameter is passed using the 'each' method.
>> I also understand how TWO parameters is passed, like in this code
>> x = { "a" => 100, "b" => 20 }
>> x.delete_if { |key, value| value < 25 }
>> p x
>>
>> Can anyone give me a very simple and executable code where:
>> NO parameters is passed, and

>
> irb(main):001:0> [0,1,2,3].each { puts "no param" }
> no param
> no param
> no param
> no param
> => [0, 1, 2, 3]


There is _one_ parameter passed - you just do not pick it up in the block.

Kind regards

robert

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

 
Reply With Quote
 
Phillip Gawlowski
Guest
Posts: n/a
 
      10-07-2010
On Thu, Oct 7, 2010 at 2:17 PM, Robert Klemme
<(E-Mail Removed)> wrote:
>> irb(main):001:0> [0,1,2,3].each { puts "no param" }
>> no param
>> no param
>> no param
>> no param
>> => [0, 1, 2, 3]

>
> There is _one_ parameter passed - you just do not pick it up in the block.


Ah, then I misunderstood the question, I guess, thinking that the OP
wanted an example of a block without a parameter enclosed in ||,
analogus to the |key,value| pair in the OP's example.

Though, do you count the array index passed into the #each block as a
parameter, or not?

--
Phillip Gawlowski

Though the folk I have met,
(Ah, how soon!) they forget
When I've moved on to some other place,
There may be one or two,
When I've played and passed through,
Who'll remember my song or my face.

 
Reply With Quote
 
Robert Klemme
Guest
Posts: n/a
 
      10-07-2010
On Thu, Oct 7, 2010 at 2:29 PM, Phillip Gawlowski
<(E-Mail Removed)> wrote:
> On Thu, Oct 7, 2010 at 2:17 PM, Robert Klemme
> <(E-Mail Removed)> wrote:
>>> irb(main):001:0> [0,1,2,3].each { puts "no param" }
>>> no param
>>> no param
>>> no param
>>> no param
>>> => [0, 1, 2, 3]

>>
>> There is _one_ parameter passed - you just do not pick it up in the block.

>
> Ah, then I misunderstood the question, I guess, thinking that the OP
> wanted an example of a block without a parameter enclosed in ||,
> analogus to the |key,value| pair in the OP's example.


Actually I am not sure what the OP *really* wanted either. I just
wanted to point out that the parameter is actually passed (which you
can see if you add a formal parameter to the block) but that the block
does not use it.

> Though, do you count the array index passed into the #each block as a
> parameter, or not?


The index is only passed with #each_index. And yes, of course it is a
parameter.

Kind regards

robert

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Could anyone give a working example using asynchat in Python3.0? davy zhang Python 0 10-22-2008 02:29 AM
Can anyone give me a hand, please? heab92 ASP .Net 0 08-19-2007 11:13 PM
who can give a simple example? Urgently need!! Flamingo Java 21 10-23-2006 11:03 PM
newbie: confused with example in Learning Python 2nd Edition: can anyone give a hint Porky Pig Jr Python 3 08-24-2004 04:02 AM
HELP! Anyone can give me example ? S300 Java 1 09-01-2003 07:03 PM



Advertisments