Benchmarks for joining string from small chunks in golang

concat_test.go

package bench

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

var validResult = "100 abc --- false 200 500"

func BenchmarkConcat(b *testing.B) {
	for i := 0; i < b.N; i++ {
		a := 100
		g := "abc"
		c := "---"
		d := "false"
		e := 200
		f := "500"
		result := strconv.Itoa(a) + " " + g + " " + c + " " + d + " " + strconv.Itoa(e) + " " + f
		if result != validResult {
			b.Fatalf("%s <> %s", result, validResult)
		}
	}
}

func BenchmarkJoin(b *testing.B) {
	for i := 0; i < b.N; i++ {
		chunks := []string{
			strconv.Itoa(100),
			"abc",
			"---",
			"false",
			strconv.Itoa(200),
			"500",
		}
		result := strings.Join(chunks, " ")
		if result != validResult {
			b.Fatalf("%s <> %s", result, validResult)
		}
	}
}

func BenchmarkBuilder(b *testing.B) {
	for i := 0; i < b.N; i++ {
		builder := strings.Builder{}
		builder.WriteString(strconv.Itoa(100))
		builder.WriteString(" ")
		builder.WriteString("abc")
		builder.WriteString(" ")
		builder.WriteString("---")
		builder.WriteString(" ")
		builder.WriteString("false")
		builder.WriteString(" ")
		builder.WriteString(strconv.Itoa(200))
		builder.WriteString(" ")
		builder.WriteString("500")

		result := builder.String()
		if result != validResult {
			b.Fatalf("%s <> %s", result, validResult)
		}
	}
}

func BenchmarkSprintf(b *testing.B) {
	for i := 0; i < b.N; i++ {
		a := 100
		g := "abc"
		c := "---"
		d := "false"
		e := 200
		f := "500"
		result := fmt.Sprintf("%d %s %s %s %d %s", a, g, c, d, e, f)
		if result != validResult {
			b.Fatalf("%s <> %s", result, validResult)
		}
	}
}


/*
go test -bench=. -benchmem concat_test.go 
goos: linux
goarch: amd64
cpu: Intel(R) Core(TM) i7-6700T CPU @ 2.80GHz
BenchmarkConcat-8        6188331               196.0 ns/op            38 B/op          3 allocs/op
BenchmarkJoin-8          6894038               174.2 ns/op            38 B/op          3 allocs/op
BenchmarkBuilder-8       6189663               188.7 ns/op            64 B/op          5 allocs/op
BenchmarkSprintf-8       2614960               468.2 ns/op            96 B/op          5 allocs/op
PASS
*/