计算函数执行时间

package main

import (
    "fmt"
    "time"
)

func f1()  {
    start := time.Now()
    for i:=1;i<9999;i++  {
        fmt.Printf("------%d--------\n",i)
    }
    end := time.Now()
    delta := end.Sub(start)
    fmt.Printf("longCalculation took this amount of time: %s\n", delta)
}




func main() {

    f1()
}