golang几种字符拼接性能分析-木庄网络博客

本文摘自网络，作者，侵删。

基准测试代码

const numbers = 10000

//fmt.Sprintf
func BenchmarkStringSprintf(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        var str string
        for j := 0; j < numbers; j++ {
            str = fmt.Sprintf("%s%d", str, j)
        }
    }
    b.StopTimer()
}

// add
func BenchmarkStringAdd(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        var str string
        for j := 0; j < numbers; j++ {
            str = str + strconv.Itoa(j)
        }
    }
}

// add
func BenchmarkStringAdd2(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        var str string
        for j := 0; j < numbers; j++ {
            str = str + fmt.Sprintf("%d", j)
        }
    }
    b.StopTimer()
}

//bytes.Buffer
func BenchmarkBytesBuffer(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        var buffer bytes.Buffer
        for j := 0; j < numbers; j++ {
            buffer.WriteString(strconv.Itoa(j))
        }
        _ = buffer.String()
    }
    b.StopTimer()
}

//strings.Builder
func BenchmarkStringBuilder(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        var builder strings.Builder
        for j := 0; j < numbers; j++ {
            builder.WriteString(strconv.Itoa(j))
        }
        _ = builder.String()
    }
    b.StopTimer()
}

//strings.Join
func BenchmarkStringJoin(b *testing.B) {
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        strs := make([]string, 0)
        for j := 0; j < numbers; j++ {
            strs = append(strs, strconv.Itoa(j))
        }
        strings.Join(strs, "")
    }
}

基准测试结果

PS D:\Users\lf\Desktop\coding\golang-study\expirement\strcat> go test -bench=".*"
goos: Windows/">windows
goarch: amd64
BenchmarkStringSprintf-8              16          68860744 ns/op
BenchmarkStringAdd-8                  18          63270089 ns/op
BenchmarkStringAdd2-8                 19          61748021 ns/op
BenchmarkBytesBuffer-8              2068            582808 ns/op
BenchmarkStringBuilder-8            2324            545157 ns/op
BenchmarkStringJoin-8                991           1075484 ns/op
PASS
ok      _/D_/Users/lf/Desktop/coding/golang-study/expirement/strcat     9.836s

这次比较的结果来看 strings.Builder > bytes.Buffer > strings.Join > string add > fmt.Sprintf