I'd like to remove all characters from string, usi开发者_开发问答ng most simple way.
For example
from "a,sd3 31ds"
to "asdds"
I cad do it something like this:
"a,sd3 31ds".gsub(/\W/, "").gsub(/\d/,"")
# => "asdds"
but it looks a little bit awkward. Maybe it is possible to merge these rexegs in one?
"a,sd3 31ds".gsub(/(\W|\d)/, "")
I would go for the regexp /[\W\d]+/
. It is potentially faster than e.g. /(\W|\d)/
.
require 'benchmark'
N = 500_000
Regexps = [ "(\\W|\\d)", "(\\W|\\d)+", "(?:\\W|\\d)", "(?:\\W|\\d)+",
"\\W|\\d", "[\\W\\d]", "[\\W\\d]+" ]
Benchmark.bm(15) do |x|
Regexps.each do | re_str |
re = Regexp.new(re_str)
x.report("/#{re_str}/:") { N.times { "a,sd3 31ds".gsub(re, "") }}
end
end
gives (with ruby 2.0.0p195 [x64-mingw32])
user system total real
/(\W|\d)/: 1.950000 0.000000 1.950000 ( 1.951437)
/(\W|\d)+/: 1.794000 0.000000 1.794000 ( 1.787569)
/(?:\W|\d)/: 1.857000 0.000000 1.857000 ( 1.855515)
/(?:\W|\d)+/: 1.638000 0.000000 1.638000 ( 1.626698)
/\W|\d/: 1.856000 0.000000 1.856000 ( 1.865506)
/[\W\d]/: 1.732000 0.000000 1.732000 ( 1.754596)
/[\W\d]+/: 1.622000 0.000000 1.622000 ( 1.617705)
You can do this with the regex "OR".
"205h2n0bn r0".gsub(/\W|\d/, "")
will do the trick :)
What about
"a,sd3 31ds".gsub(/\W|\d/,"")
You can always join regular expressions by |
to express an "or".
You can try this regex:
\P{L}
not Unicode letter, but I don't know, does Ruby support this class.
A non regex solution:
"a,sd3 31ds".delete('^A-Za-z')
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