Go 字符串各种拼接方案的性能对比（实操最佳方案）

package main

import (
    "bytes"
    "fmt"
    "strings"
    "testing"
)

const LOOP = 1000


// BenchmarkStringAdd + 号拼接
func BenchmarkStringAdd(b *testing.B) {
    for n := 0; n < b.N; n++ {
        var s string
        for j := 0; j < LOOP; j++ {
            s += "gopher"
        }
    }
}

// BenchmarkStringBytesBufferAdd bytes.Buffer 拼接
func BenchmarkStringFmtAdd(b *testing.B) {
    for i := 0; i < b.N; i++ {
        var s string
        for j := 0; j < LOOP; j++ {
            s = fmt.Sprintf("%sgopher", s)
        }
    }
}
// BenchmarkStringBuilderAdd strings.Builder 拼接
func BenchmarkStringBuilderAdd(b *testing.B) {
    for i := 0; i < b.N; i++ {
        var builder strings.Builder
        for j := 0; j < LOOP; j++ {
            builder.WriteString("gopher")
        }
        _ = builder.String()
    }
}

// BenchmarkStringBytesBufferAdd bytes.Buffer 拼接
func BenchmarkStringBytesBufferAdd(b *testing.B) {
    for i := 0; i < b.N; i++ {
        var builder bytes.Buffer
        for j := 0; j < LOOP; j++ {
            builder.WriteString("gopher")
        }
        _ = builder.String()
    }
}

# go test -bench='BenchmarkStringBuilderAdd'  -cpu=2 -count=1 -benchmem .
BenchmarkStringBuilderAdd-2       259993              4663 ns/op           24824 B/op         14 allocs/op
PASS
ok      learn-go       4.600s

# go test -bench='BenchmarkStringFmtAdd'  -cpu=2 -count=1 -benchmem .
BenchmarkStringFmtAdd-2             2973            404782 ns/op         3231129 B/op       2002 allocs/op
PASS
ok      learn-go       2.455s

# go test -bench='BenchmarkStringBuilderAdd'  -cpu=2 -count=1 -benchmem .
BenchmarkStringBuilderAdd-2       256581              4671 ns/op           24824 B/op         14 allocs/op
PASS
ok      learn-go       2.419s

# go test -bench='BenchmarkStringBytesBufferAdd'  -cpu=2 -count=1 -benchmem .
BenchmarkStringBytesBufferAdd-2           206992              5818 ns/op           22464 B/op    9 allocs/op
PASS
ok      it******.com/learn-go       2.459s