go test -bench=. string_test.go

string_format_benchmark.go

package string_test

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

const numbers = 100

// 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)
		}
	}
	b.StopTimer()
}

// bytes.Buffer
func BenchmarkStringBuffer(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()
}