Slicing arrays


#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

On 6/6/06, Paul D. Kraus removed_email_address@domain.invalid wrote:

fields.
myarray = mystring.split(’,’).splice(1,3…5)

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


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:

fields.

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