Shorter form of concat

ruby-talk
1

the following line will concat "1" all the way to "10"... but is there
a shorter way... like x . y or must it be this long?

p (1..10).inject{|x,y| x.to_s + y.to_s}

also... x.to_s + y
won't cause y to convert to a string?

···

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2

SpringFlowers AutumnMoon wrote:

the following line will concat "1" all the way to "10"... but is there
a shorter way... like x . y or must it be this long?

p (1..10).inject{|x,y| x.to_s + y.to_s}

(1..10).to_a.join

also... x.to_s + y
won't cause y to convert to a string?

No.

···

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3

Tim Hunter wrote:

SpringFlowers AutumnMoon wrote:

the following line will concat "1" all the way to "10"... but is there
a shorter way... like x . y or must it be this long?

p (1..10).inject{|x,y| x.to_s + y.to_s}

(1..10).to_a.join

what i mean is, any shorter way to concat two numbers? something
similar to x . y

···

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4

This is not pretty, but...

x = 1
y = 10
string = "#{x}#{y}"
puts string => 110

I'm not sure I'd use that in production code, but there it is...

Ben

···

On Feb 3, 2008 11:23 PM, SpringFlowers AutumnMoon <summercoolness@gmail.com> wrote:

Tim Hunter wrote:
> SpringFlowers AutumnMoon wrote:
>> the following line will concat "1" all the way to "10"... but is there
>> a shorter way... like x . y or must it be this long?
>>
>>
>> p (1..10).inject{|x,y| x.to_s + y.to_s}
>
> (1..10).to_a.join

what i mean is, any shorter way to concat two numbers? something
similar to x . y

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

5

SpringFlowers AutumnMoon wrote:

Tim Hunter wrote:

SpringFlowers AutumnMoon wrote:

the following line will concat "1" all the way to "10"... but is there
a shorter way... like x . y or must it be this long?

p (1..10).inject{|x,y| x.to_s + y.to_s}

(1..10).to_a.join

what i mean is, any shorter way to concat two numbers? something
similar to x . y

class Fixnum
  def a(num)
    return sprintf("%s%s", self, num)
  end
end

x = 3
y = 4
puts x.a(y)

--output:--
34

···

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6

7stud -- wrote:

class Fixnum
  def a(num)
    return sprintf("%s%s", self, num)
  end
end

x = 3
y = 4
puts x.a(y)

--output:--
34

thanks. or this one works too:

p (1..10).inject{|x,y| "#{x}#{y}"}

···

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7

I think its better with a .to_a.join, depending on what you want it could be
more legible than the .inject one and equally customizable.

···

On Feb 4, 2008 7:53 AM, SpringFlowers AutumnMoon <summercoolness@gmail.com> wrote:

7stud -- wrote:

> class Fixnum
> def a(num)
> return sprintf("%s%s", self, num)
> end
> end
>
> x = 3
> y = 4
> puts x.a(y)
>
> --output:--
> 34

thanks. or this one works too:

p (1..10).inject{|x,y| "#{x}#{y}"}
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8

If you use #inject, then you should rather do

irb(main):003:0> (1..10).inject("") {|s,x| s << x.to_s}
=> "12345678910"

or

irb(main):004:0> require 'stringio'
=> true
irb(main):005:0> (1..10).inject(StringIO.new) {|s,x| s << x}.string
=> "12345678910"

This is - at least in theory - much more efficient than repeated string interpolation.

Kind regards

  robert

···

On 04.02.2008 10:53, SpringFlowers AutumnMoon wrote:

7stud -- wrote:

class Fixnum
  def a(num)
    return sprintf("%s%s", self, num)
  end
end

x = 3
y = 4
puts x.a(y)

--output:--
34

thanks. or this one works too:

p (1..10).inject{|x,y| "#{x}#{y}"}

9

As does this:

(1..10).map {|n| n.to_s}.join

···

On Feb 4, 4:53 am, SpringFlowers AutumnMoon <summercooln...@gmail.com> wrote:

thanks. or this one works too:

p (1..10).inject{|x,y| "#{x}#{y}"}

10

Yes :slight_smile: I use #map on ranges frequently.

···

On Feb 4, 2008 3:34 PM, Karl von Laudermann <doodpants@mailinator.com> wrote:

On Feb 4, 4:53 am, SpringFlowers AutumnMoon <summercooln...@gmail.com> > wrote:
> thanks. or this one works too:
>
> p (1..10).inject{|x,y| "#{x}#{y}"}

As does this:

(1..10).map {|n| n.to_s}.join