slice刪除元素的性能對比

package?main

import?(
???"testing"
)

//?第一種
func?BenchmarkMake(t?*testing.B)?{
???t.ResetTimer()

???origin?:=?[]int{1,?2,?3,?4,?5,?6,?7,?8,?9,?10}
???for?i?:=?0;?i?<?t.N;?i++?{
??????target?:=?make([]int,?len(origin))
??????for?_,?item?:=?range?origin?{
?????????if?item?!=?6?{
????????????target?=?append(target,?item)
?????????}
??????}
???}
}

//?第二種
func?BenchmarkReuse(t?*testing.B)?{
???t.ResetTimer()

???origin?:=?[]int{1,?2,?3,?4,?5,?6,?7,?8,?9,?10}
???for?i?:=?0;?i?<?t.N;?i++?{
??????target?:=?origin[:0]
??????for?_,?item?:=?range?origin?{
?????????if?item?!=?6?{
????????????target?=?append(target,?item)
?????????}
??????}
???}
}

//?第三種
func?BenchmarkEditOne(t?*testing.B)?{
???t.ResetTimer()

???origin?:=?[]int{1,?2,?3,?4,?5,?6,?7,?8,?9,?10}
???for?i?:=?0;?i?<?t.N;?i++?{
??????for?i?:=?0;?i?<?len(origin);?i++?{
?????????if?origin[i]?==?6?{
????????????origin?=?append(origin[:i],?origin[i+1:]...)
????????????i--?//?maintain?the?correct?index
?????????}
??????}
???}
}

//?第四種
func?BenchmarkFuck(t?*testing.B)?{
???t.ResetTimer()

???origin?:=?[]int{1,?2,?3,?4,?5,?6,?7,?8,?9,?10}
???for?i?:=?0;?i?<?t.N;?i++?{
??????for?i?:=?0;?i?<?len(origin);?i++?{
?????????if?origin[i]?==?6?{
????????????tempV?:=?origin[i]
????????????origin?=?append(append(origin[:i],?origin[i+1:]...),?tempV)
????????????//i--?//?maintain?the?correct?index
?????????}
??????}
???}
}

執(zhí)行命令：go test main6_test.go -v -bench=.

輸出：

E:\go_work_dir\test\x>go test main6_test.go -v -bench=.
goos: windows
goarch: amd64
BenchmarkMake-8???????? 10000000?????????????? 146 ns/op
BenchmarkReuse-8??????? 100000000?????????????? 10.9 ns/op
BenchmarkEditOne-8????? 200000000??????????????? 7.69 ns/op
BenchmarkFuck-8???????? 100000000?????????????? 13.4 ns/op
PASS
ok????? command-line-arguments? 8.592s

命令：go test main6_test.go -v -bench=. -benchtime=3s -benchmem

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原文：

https://www.jianshu.com/p/d276aa7300d1