Removing duplicate characters
An interesting string method was brought to my attention on the ruby-talk mailing list: string.squeeze. It removes duplicate characters in a string, and performs better than regular expressions or splitting-joining, to boot. Craig posted some benchmarks:
require 'benchmark'
n = 1_000_000
Benchmark.bm(10) do |x|
x.report("gsub") { n.times do
"This is a test string.".gsub(/ +/, ' ')
end
}
x.report("gsub!") { n.times do
"This is a test string.".gsub!(/ +/, ' ')
end
}
x.report("split.join") { n.times do
"This is a test string.".split.join(' ')
end
}
x.report("squeeze.strip") { n.times do
"This is a test string.".squeeze(' ').strip
end
}
end
user system total real
gsub 4.470000 0.040000 4.510000 ( 4.578173)
gsub! 4.390000 0.020000 4.410000 ( 4.468695)
split.join 3.500000 0.020000 3.520000 ( 3.556669)
squeeze.strip 1.980000 0.010000 1.990000 ( 2.003622)
Nice!
