Newb question

ruby-talk
1

Why does this

p 3.times {|i| puts i}

produce

0
1
2
3

???

2

Try

p 2.times {|i| puts "Number:#{i}"}

u will see the last line is the returncode of i from the last loop

Rong schrieb:

···

Why does this

p 3.times {|i| puts i}

produce

0
1
2
3

???

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Jan Pilz (e-mail: Jan.Pilz@osp-dd.de)

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3

The loop outputs 0, 1, and 2.

The 'p' outputs the value of the entire statement. The times method returns the value of its receiver, which is 3 in this case.

Regards

Dave

···

On Sep 8, 2008, at 12:53 AM, Rong wrote:

p 3.times {|i| puts i}

produce

0
1
2
3

4

try the following:

a = 3.times {|i| puts i}
puts "a = #{a}"

martin

···

On Sun, Sep 7, 2008 at 10:53 PM, Rong <ron.green@gmail.com> wrote:

Why does this

p 3.times {|i| puts i}

produce

0
1
2
3

5

Ron Green wrote:

Why does this

p 3.times {|i| puts i}

produce

0
1
2
3

???

I think that a way to see what they are saying more clearly is thus:

ar = Array.new
3.times {|i| ar << i}
p ar

=> [0, 1, 2]

It does things as expected but internally to the block it has that last
bit.

I hope that helps.

···

--
Posted via http://www.ruby-forum.com/\.

6

But why is it incrementing?

···

On Sep 8, 1:00 am, Dave Thomas <d...@pragprog.com> wrote:

On Sep 8, 2008, at 12:53 AM, Rong wrote:

> p 3.times {|i| puts i}

> produce

> 0
> 1
> 2
> 3

The loop outputs 0, 1, and 2.

The 'p' outputs the value of the entire statement. The times method
returns the value of its receiver, which is 3 in this case.

Regards

Dave

7

Because you asked it to?

ri Integer.times
---------------------------------------------------------- Integer#times
      int.times {|i| block } => int

···

On Sep 8, 2008, at 1:11 AM, Rong wrote:

But why is it incrementing?

------------------------------------------------------------------------
      Iterates block int times, passing in values from zero to int - 1.

         5.times do |i|
           print i, " "
         end

      produces:

         0 1 2 3 4

8

It's not. n.times {|i| ... } calls the block with values from 0 to
n-1, then returns n. The loop variable isn't incremented that one
final time, if that's what you were asking.

martin

···

On Sun, Sep 7, 2008 at 11:11 PM, Rong <ron.green@gmail.com> wrote:

But why is it incrementing?