golang?字符串拼接方法對(duì)比分析

更新時(shí)間：2023年09月04日 10:51:59 作者：guyan0319

這篇文章主要為大家介紹了golang?字符串拼接方法對(duì)比分析,有需要的朋友可以借鑒參考下,希望能夠有所幫助,祝大家多多進(jìn)步,早日升職加薪

字符串拼接

字符串拼接有以下幾種方法

加號(hào)+
fmt.Sprintf
strings.Join
bytes.Buffer
strings.Builder 此方法為官方推薦

新建單元測(cè)試文件string_test.go

package test
import (
    "bytes"
    "fmt"
    "strings"
    "testing"
)
func BenchmarkFmtSprintf(b *testing.B) {
    for i := 0; i < b.N; i++ {
        s := fmt.Sprintf("%s%s", "abcdefghijklmnopqrstuvwxyz", "123456789")
        fmt.Errorf(s)
    }
}
func BenchmarkAdd(b *testing.B) {
    for i := 0; i < b.N; i++ {
        s := "abcdefghijklmnopqrstuvwxyz" +"123456789"
        fmt.Errorf(s)
    }
}
func BenchmarkStringsJoin(b *testing.B) {
    for i := 0; i < b.N; i++ {
        s := strings.Join([]string{"abcdefghijklmnopqrstuvwxyz","123456789"}, "")
        fmt.Errorf(s)
    }
}
func BenchmarkBuffer(b *testing.B) {
    for i := 0; i < b.N; i++ {
        buf := bytes.Buffer{}
        buf.WriteString("abcdefghijklmnopqrstuvwxyz")
        buf.WriteString("123456789")
        fmt.Errorf(buf.String())
    }
}
func BenchmarkBuilder(b *testing.B) {
    for i := 0; i < b.N; i++ {
        builder := strings.Builder{}
        builder.WriteString("abcdefghijklmnopqrstuvwxyz")
        builder.WriteString("123456789")
        fmt.Errorf(builder.String())
    }
}

執(zhí)行

go test string_test.go -benchmem -bench=".*"

結(jié)果：

BenchmarkFmtSprintf-4 2962962 400.6 ns/op 112 B/op 3 allocs/op
BenchmarkAdd-4 6629833 207.7 ns/op 64 B/op 2 allocs/op
BenchmarkStringsJoin-4 4255318 291.6 ns/op 112 B/op 3 allocs/op
BenchmarkBuffer-4 2948402 368.3 ns/op 176 B/op 4 allocs/op
BenchmarkBuilder-4 3149605 352.1 ns/op 160 B/op 4 allocs/op
PASS
ok command-line-arguments 8.219s
執(zhí)行效率排序+>join>fmt.Sprintf>strings.Builder>bytes.Buffer

新建單元測(cè)試文件string2_test.go

package test
import (
    "bytes"
    "fmt"
    "strings"
    "testing"
)
func BenchmarkAdd2(b *testing.B) {
    s:= "abcdefghijklmnopqrstuvwxyz"
    for i := 0; i < b.N; i++ {
        s += "abcdefghijklmnopqrstuvwxyz"
    }
    fmt.Errorf(s)
}
func BenchmarkBuffer2(b *testing.B) {
    buf := bytes.Buffer{}
    for i := 0; i < b.N; i++ {
        buf.WriteString("abcdefghijklmnopqrstuvwxyz")
    }
    fmt.Errorf(buf.String())
}
func BenchmarkBuilder2(b *testing.B) {
    builder := strings.Builder{}
    for i := 0; i < b.N; i++ {
        builder.WriteString("abcdefghijklmnopqrstuvwxyz")
    }
    fmt.Errorf(builder.String())
}

執(zhí)行

go test string2_test.go -benchmem -bench=".*"

結(jié)果：

goos: windows
goarch: amd64
cpu: Intel(R) Core(TM) i7-6500U CPU @ 2.50GHz
BenchmarkAdd2-4 10000 101400 ns/op 133806 B/op 1 allocs/op
BenchmarkBuffer2-4 15974260 79.25 ns/op 145 B/op 0 allocs/op
BenchmarkBuilder2-4 17142856 59.38 ns/op 189 B/op 0 allocs/op
PASS
ok command-line-arguments 4.912s
執(zhí)行效率排序：strings.Builder>bytes.Buffer>加號(hào)
且strings.Builder和bytes.Buffer分配內(nèi)存大小和次數(shù)，要比加號(hào)效率更好