Fastest way to check if a string matches a regexp in ruby?

Question

What is the fastest way to check if a string matches a regular expression in Ruby?

My problem is that I have to \"egrep\" through a huge list of strings to find whic

Answer 1

This is a simple benchmark:

require 'benchmark'

"test123" =~ /1/
=> 4
Benchmark.measure{ 1000000.times { "test123" =~ /1/ } }
=>   0.610000   0.000000   0.610000 (  0.578133)

"test123"[/1/]
=> "1"
Benchmark.measure{ 1000000.times { "test123"[/1/] } }
=>   0.718000   0.000000   0.718000 (  0.750010)

irb(main):019:0> "test123".match(/1/)
=> #<MatchData "1">
Benchmark.measure{ 1000000.times { "test123".match(/1/) } }
=>   1.703000   0.000000   1.703000 (  1.578146)

So =~ is faster but it depends what you want to have as a returned value. If you just want to check if the text contains a regex or not use =~