print_test.go

package main

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

var loopnum int = 1000000

func BenchmarkPrint_Join(b *testing.B) {
	strs := makeDummyStrings(loopnum)
	b.ResetTimer()

	fmt.Fprintln(os.Stderr, strings.Join(strs, "\n"))
}

func BenchmarkPrint_Foreach(b *testing.B) {
	strs := makeDummyStrings(loopnum)
	b.ResetTimer()

	for _, s := range strs {
		fmt.Fprintln(os.Stderr, s)
	}
}

func makeDummyStrings(n int) []string {
	strs := make([]string, n)
	for i := 0; i < n; i++ {
		strs[i] = strconv.Itoa(i)
	}
	return strs
}

$ go test -bench . -benchmem 2> /dev/null
BenchmarkPrint_Join-4           2000000000               0.01 ns/op            0 B/op          0 allocs/op
BenchmarkPrint_Foreach-4        1000000000               0.55 ns/op            0 B/op          0 allocs/op
PASS
ok      ...  12.929s