Ruby: increment all integers in a string by +1
I am looking for a succinct way to increment all the integers found in a string by +1 and return the full string.
For example:
"1 plus 2 and 10 and 100"
needs to become
"2 plus 3 and 11 and 101"
I can find all the integers very easily with
"1 plus 2 and 10 and 100".scan(/\d开发者_如何学Python+/)
but I'm stuck at this point trying to increment and put the parts back together.
Thanks in advance.
You could use the block form of String#gsub:
str = "1 plus 2 and 10 and 100".gsub(/\d+/) do |match|
match.to_i + 1
end
puts str
Output:
2 plus 3 and 11 and 101
The gsub
method can take in a block, so you can do this
>> "1 plus 2 and 10 and 100".gsub(/\d+/){|x|x.to_i+1}
=> "2 plus 3 and 11 and 101"
The thing with your regex is that it doesn't preserve your original string in the chain in order to put it back. What I did was to split it using spaces, detect which are words or integers using w.to_i != 0
(not counting 0 as an integer, you might want to improve this), add one, and join it back:
s = "1 plus 2 and 10 and 100"
s.split(" ").map{ |e| if (e.to_i != 0) then e.to_i+1 else e end }.join(" ")
=> "2 plus 3 and 11 and 101"
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