Joining strings with + is faster than fmt.Sprintf

benchmark_test.go

package benchmark_test

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

var label = "FOOBARBAZ"

func BenchmarkWithSprintf(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_ = fmt.Sprintf("%d/%s", i, label)
	}
}

func BenchmarkWithPlus(b *testing.B) {
	for i := 0; i < b.N; i++ {
		_ = strconv.Itoa(i) + "/" + label
	}
}

/* RESULT
$ go test -bench . -benchmem
goos: darwin
goarch: amd64
pkg: practice/go-benchmark
BenchmarkWithSprintf-8          10000000               147 ns/op              54 B/op          3 allocs/op
BenchmarkWithPlus-8             30000000                43.8 ns/op             7 B/op          0 allocs/op
PASS
ok      practice/go-benchmark   2.986s
*/