Slicing arrays

ruby-talk
1

if have a text file I am parsing. I am using split to break the line into an
array.
I want to then use splice to pick and choose the fields that I one.

so for example i have a string.
mystring = '1,2,3,4,5,6'

then i want to get an array but I only want the 2 field and the last three
fields.
myarray = mystring.split(',').splice(1,3..5)

This breaks.

I can get the range 3..5 or i get the element splice(1).

Am I missing something?

Do i just build the array as normal and then make a new array from the
elements I need?

Paul

2

Honestly I do not know about a splice method for Arrays

here is a less elegant way

    m = mystring.split(',')
    m[1..1] + m[3..5]
or in case you want to specify your ranges in a string
   "1,3..5".split(",").map{|x| x.split("..")}.flatten.map{|x| m[x.to_i]}

or you write your own splice method

class Array
    def splice( *args )
        args.map{ |arg|
            case arg
                when Integer
                    arg
                when Range
                    arg.to_a
                else
                    raise TypeError, "blah #{arg} is not to our liking"
            end # case arg
        }.flatten.map{ |a| self[a] }
    end # def splice( *args )
end # class Array

well now I know one :wink:
Hope that helps
Robert

···

On 6/6/06, Paul D. Kraus <paul.kraus@gmail.com> wrote:

if have a text file I am parsing. I am using split to break the line into
an
array.
I want to then use splice to pick and choose the fields that I one.

so for example i have a string.
mystring = '1,2,3,4,5,6'

then i want to get an array but I only want the 2 field and the last three
fields.
myarray = mystring.split(',').splice(1,3..5)

--
Deux choses sont infinies : l'univers et la bêtise humaine ; en ce qui
concerne l'univers, je n'en ai pas acquis la certitude absolue.

- Albert Einstein

3

Paul D. Kraus wrote:

if have a text file I am parsing. I am using split to break the line into an
array.
I want to then use splice to pick and choose the fields that I one.

so for example i have a string.
mystring = '1,2,3,4,5,6'

then i want to get an array but I only want the 2 field and the last three
fields.
myarray = mystring.split(',').splice(1,3..5)

This breaks.

I can get the range 3..5 or i get the element splice(1).

Am I missing something?

Do i just build the array as normal and then make a new array from the
elements I need?

Paul

Have you tried the values_at method?

4

Have you tried the values_at method?

Arrgh I normally always read the doc, sorry OP forget about my splice it is
already here

values_at

great job!

Robert