Ruby 我们的阵列收集速度似乎更快) a = [ "a", "b", "c", "d" ] a.collect {|x| x + "!" } #=> ["a!", "b!", "c!", "d!"] a
我们的阵列收集速度似乎更快)Ruby 我们的阵列收集速度似乎更快) a = [ "a", "b", "c", "d" ] a.collect {|x| x + "!" } #=> ["a!", "b!", "c!", "d!"] a ,ruby,arrays,map,collect,Ruby,Arrays,Map,Collect,我们的阵列收集速度似乎更快) a = [ "a", "b", "c", "d" ] a.collect {|x| x + "!" } #=> ["a!", "b!", "c!", "d!"] a #=> ["a", "b", "c", "d"] static VALUE rb_ary_collect(VALUE ary) { long i; VALUE collect; RETURN_SIZED_
a = [ "a", "b", "c", "d" ]
a.collect {|x| x + "!" } #=> ["a!", "b!", "c!", "d!"]
a #=> ["a", "b", "c", "d"]
static VALUE
rb_ary_collect(VALUE ary)
{
long i;
VALUE collect;
RETURN_SIZED_ENUMERATOR(ary, 0, 0, ary_enum_length);
collect = rb_ary_new2(RARRAY_LEN(ary));
for (i = 0; i < RARRAY_LEN(ary); i++) {
rb_ary_push(collect, rb_yield(RARRAY_AREF(ary, i)));
}
return collect;
}
require 'benchmark'
h = { abc: 'hello', 'another_key' => 123, 4567 => 'third' }
a = 1..10
many = 500_000
Benchmark.bm do |b|
GC.start
b.report("hash keys collect") do
many.times do
h.keys.collect(&:to_s)
end
end
GC.start
b.report("hash keys map") do
many.times do
h.keys.map(&:to_s)
end
end
GC.start
b.report("array collect") do
many.times do
a.collect(&:to_s)
end
end
GC.start
b.report("array map") do
many.times do
a.map(&:to_s)
end
end
end
user system total real
hash keys collect 0.540000 0.000000 0.540000 ( 0.570994)
hash keys map 0.500000 0.010000 0.510000 ( 0.517126)
array collect 1.670000 0.020000 1.690000 ( 1.731233)
array map 1.680000 0.020000 1.700000 ( 1.744398)
Array.instance_method(:map) == Array.instance_method(:collect)
=> true