How to extract float numbers from a string in ruby? [closed]

问题

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Closed 8 years ago.

I have string with an amount different currencies in it, e.g,

"454,54$", "Rs566.33", "discount 88,0$" etc.

The pattern is not consistent and I want to extract only float numbers from the string and the currency.

How I can achieve this in Ruby ?

回答1:

You can use this regex to match floating point numbers in the two formats you posted: -

(\d+[,.]\d+)

See Demo on Rubular

回答2:

you can try this:

["454,54$", "Rs566.33", "discount 88,0$", "some string"].each do |str|
  # making sure the string actually contains some float
  next unless float_match = str.scan(/(\d+[.,]\d+)/).flatten.first
  # converting matched string to float
  float = float_match.tr(',', '.').to_f
  puts "#{str} => %.2f" % float
end

# => 454,54$ => 454.54
# => Rs566.33 => 566.33
# => discount 88,0$ => 88.00

Demo on CIBox

来源：https://stackoverflow.com/questions/13706706/how-to-extract-float-numbers-from-a-string-in-ruby