从 Ruby 中的字符串中提取数字

我用这个代码:

s = line.match( /ABCD(\d{4})/ ).values_at( 1 )[0]

从字符串中提取数字，如:

ABCD1234
ABCD1235
ABCD1236

等等。

它可以工作，但是我想知道在 Ruby 中我还有什么其他选择？

我的代码:

ids = []
someBigString.lines.each {|line|
ids << line.match( /ABCD(\d{4})/ ).values_at( 1 )[0]
}
88619 次浏览
小开
最佳答案 
a.map {|x| x[/\d+/]}
小开

there is even simpler solution

line.scan(/\d+/).first
小开

There are many Ruby ways as per http://www.ruby-forum.com/topic/125709

  1. line.scan(/\d/).join('')
  2. line.gsub(/[^0-9]/, '')
  3. line.gsub(/[^\d]/, '')
  4. line.tr("^0-9", '')
  5. line.delete("^0-9")
  6. line.split(/[^\d]/).join
  7. line.gsub(/\D/, '')

Try each on you console.

Also check the benchmark report in that post.

小开

Another solution may be to write:

myString = "sami103"
myString.each_char{ |c| myString.delete!(c) if c.ord<48 or c.ord>57 } #In this case, we are deleting all characters that do not represent numbers.

Now, if you type

myNumber = myString.to_i #or myString.to_f

This should return a

小开 
your_input = "abc1cd2"
your_input.split(//).map {|x| x[/\d+/]}.compact.join("").to_i

This should work.

小开

To extract number part from a string use the following:

str = 'abcd1234'
/\d+/.match(str).try(:[], 0)

It should return 1234

小开

The simplest and fastest way is use regular expression to parse the integers out from the string.

str = 'abc123def456'


str.delete("^0-9")
=> "123456"


str.tr("^0-9","")
=> "123456"

Comparing benchmarks on a long string with some of the other solutions provided here, we can see tr is fastest with delete close 2nd.

require 'benchmark'


n = 2
string = [*'a'..'z'].concat([*1..1_000_000].map(&:to_s)).shuffle.join


Benchmark.bmbm do |x|
x.report('scan') do
n.times {string.scan(/\d/).join}
end
x.report('gsub') do
n.times {string.gsub(/[^\d]/,"")}
end
x.report('gsub2') do
n.times {string.gsub(/\D/, '')}
end
x.report('tr') do
n.times {string.tr("^0-9","")}
end
x.report('delete') do
n.times {string.delete('^0-9')}
end
x.report('split') do
n.times {string.split(/[^\d]/).join}
end
end


Rehearsal ------------------------------------------
scan     3.509973   0.187274   3.697247 (  3.717773)
gsub     0.229568   0.002790   0.232358 (  0.233961)
gsub2    0.307728   0.013435   0.321163 (  0.390262)
tr       0.021395   0.000223   0.021618 (  0.022297)
delete   0.021290   0.002280   0.023570 (  0.024365)
split    0.284935   0.010274   0.295209 (  0.299865)
--------------------------------- total: 4.591165sec


user     system      total        real
scan     3.146615   0.126009   3.272624 (  3.281860)
gsub     0.211263   0.001515   0.212778 (  0.213170)
gsub2    0.208482   0.000424   0.208906 (  0.209339)
tr       0.015228   0.000086   0.015314 (  0.015387)
delete   0.015786   0.000128   0.015914 (  0.016050)
split    0.205096   0.002736   0.207832 (  0.208380)

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