Splitting array and get desired elements

Question

If I have this array:

["1","2","3,a","4,b"]

how can I get this array from it?

["1","2","3","4"].

Try something first, then we'll help you. If you don't want to spend time, why should we? — Sergio Tulentsev, Mar 21 '13 at 05:32

score 9 · Answer 1 · edited Mar 21 '13 at 06:13

9

Assuming you have all integers, (If not I guess you get the idea :))

["1","2","3,a","4,b"].collect {|i| i.to_i}

edited Mar 21 '13 at 06:13

the Tin Man

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answered Mar 21 '13 at 06:01

sameera207

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+1. The only answer to this point that actually looks like Ruby code. – the Tin Man Mar 21 '13 at 06:16
1

`i.to_i.to_s` would be more exact, because author wants an array of strings, not an array of ints. But anyway, this code is much better then the java code in the accepted answer. – DNNX Mar 21 '13 at 07:25
Or just `.collect(&:to_i)`. – potashin Jul 22 '15 at 04:02

score 3 · Answer 2 · answered Mar 21 '13 at 07:34

3

With an array like:

ary = ["1","2","3,a","4,b"]

I'd use:

ary.map{ |s| s[/\A(\d+)/, 1] }

Which results in:

[
    [0] "1",
    [1] "2",
    [2] "3",
    [3] "4"
]

It simply finds the numerics at the start of the strings and returns them in a new array.

answered Mar 21 '13 at 07:34

the Tin Man

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+1 wow, even more cleaner, (thats why I love ruby :)) – sameera207 Mar 21 '13 at 08:37
Probably the best, but nothing in the sample input really implies that \A is necessary. Maybe just /\d+/ – pguardiario Mar 21 '13 at 13:50
It's there to anchor for speed and to force accuracy. – the Tin Man Mar 21 '13 at 15:03

score 1 · Answer 3 · answered Mar 21 '13 at 07:39

1

Try:

["1","2","3,a","4,b"].map(&:to_i)
=> [1, 2, 3, 4]

to get array of strings

["1","2","3,a","4,b"].map(&:to_i).map(&:to_s)
=> ["1", "2", "3", "4"]

answered Mar 21 '13 at 07:39

shweta

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score 0 · Accepted Answer · answered Mar 21 '13 at 05:59

0

This should also works...

array=["1","2","3,a","4,b"]
  for i in 0..array.length()-1
    if array[i].include?(",")
      ab=array[i].split(",")
      array[i]=ab[0]
    end

  end
print array #["1","2","3","4"]

answered Mar 21 '13 at 05:59

ѕтƒ

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This works, but is almost as unRubylike as possible. I guess worse would be using .index instead of .include? – glenn mcdonald Mar 21 '13 at 10:56

Rubyist · Answer 5 · 2013-03-21T06:33:03.070

-2

Try this delete option :

irb(main):014:0> a = ["101","2zd","3,a","10,ab"]
=> ["101", "2zd", "3,a", "10,ab"]
irb(main):015:0> count = a.count
irb(main):016:0> for i in 0..count 
irb(main):017:1> puts a[i].delete("^0-9")
irb(main):018:1> end
101
2
3
10

UPDATED Code ( Use of Each Loop - Thanks to the Tin Man)

irb(main):005:0>  a = ["101","2zd","3,a","10,ab"]
=> ["101", "2zd", "3,a", "10,ab"]
irb(main):006:0> b = []
=> []
irb(main):007:0> a.each do |t|
irb(main):008:1* b << t.delete("^0-9")
irb(main):009:1> end
=> ["101", "2zd", "3,a", "10,ab"]
irb(main):010:0> puts b
101
2
3
10
=> nil

edited Mar 21 '13 at 06:33

answered Mar 21 '13 at 05:53

Rubyist

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`for` is not idiomatic in Ruby. Consider using `each` or `map` instead. – the Tin Man Mar 21 '13 at 06:15
Thank a lot @theTinMan for your suggestion, please have a look at http://stackoverflow.com/questions/5677081/ruby-difference-between-a-for-loop-and-an-each-loop – Rubyist Mar 21 '13 at 06:22
1

Yes, http://stackoverflow.com/a/5677251/128421 says the same thing. – the Tin Man Mar 21 '13 at 06:27

Splitting array and get desired elements

5 Answers5