string 中的一些优化事项

import (
    "testing"
    "fmt"
)

var (
    str = "hello gohpers!"
    sep = ","
)

func BenchmarkFmt(b *testing.B) {
    for i := 0; i < b.N; i++ {
        _ = fmt.Sprint("%s%s%s%s%s", str, sep, str, sep, str)
    }
}

func BenchmarkPlus(b *testing.B) {
    for i := 0; i < b.N; i++ {
        _ = str + sep + str + sep + str
    }
}