go 的时间操作

package main

import (
	"fmt"
	"time"
)

func testTime() {
	now := time.Now()
	fmt.Printf("current time: %v\n ", now)
	year := now.Year()
	month := now.Month()
	day := now.Day()
	hour := now.Hour()
	minute := now.Minute()
	second := now.Second()
	fmt.Printf("时间字符串%05d-%02d-%02d %02d:%02d:%02d\n ", year, month, day, hour, minute, second)
	fmt.Printf("类型%T,%T,%T %T,%T,%T\n ", year, month, day, hour, minute, second)
	// 上面的%05d表示填充符号,不足5位用0填充,满足了就不管了了

	timestamp := now.Unix()
	fmt.Printf("timestamp is:%d\n", timestamp)
}

// # 时间戳,从1970年到现在的时间的秒数,时间戳数字转化为时间格式
func testTimestamp(timestamp int64) {
	timeObj := time.Unix(timestamp, 0)
	year := timeObj.Year()
	month := timeObj.Month()
	day := timeObj.Day()
	hour := timeObj.Hour()
	minute := timeObj.Minute()
	second := timeObj.Second()
	fmt.Printf("current timestamp :%d\n", timestamp)
	fmt.Printf("%02d-%02d-%02d  %02d:%02d:%02d \n ", year, month, day, hour, minute, second)
}

func processTask() {
	fmt.Printf("do task\n")
}

// 定时器
func testTicker() {
	ticker := time.Tick(5 * time.Second) //每1秒,会把当前时间放入定时器管道里面
	for i := range ticker {
		fmt.Printf("这是i: %v\n", i)
		processTask()
	}
}

func testConst() {
	fmt.Printf("nano second :%d\n", time.Nanosecond)   // 纳秒
	fmt.Printf("micro second :%d\n", time.Microsecond) // 微秒
	fmt.Printf("milli second :%d\n", time.Millisecond) // 毫秒
	fmt.Printf("second :%d\n", time.Second)            // 秒
}

func testFormat() {
	now := time.Now()
	timeStr := now.Format("2006-01-02 15:04:05") // 用format格式化时间,年月日必须是2016年,1月2日,go语言诞生的时间,以这个2006-01-02 15:04:05时间作为模板
	fmt.Printf("01>>time :%s\n", timeStr)
	timeStr = now.Format("2006-1-2 15:04:05") // 用format格式化时间,年月日必须是2016年,1月2日,go语言诞生的时间
	fmt.Printf("02>>time :%s\n", timeStr)
	timeStr = now.Format("2006/01/02 15:04:05") // 用format格式化时间,年月日必须是2016年,1月2日,go语言诞生的时间
	fmt.Printf("03>>time :%s\n", timeStr)
	timeStr = now.Format("01/02/2006 15:04:05") // 用format格式化时间,年月日必须是2016年,1月2日,go语言诞生的时间
	fmt.Printf("04>>time :%s\n", timeStr)
	timeStr = now.Format("01/02/2006 3:04:05") // 用format格式化时间,下午3点,12小时的格式
	fmt.Printf("05>>time :%s\n", timeStr)
}

func testFormat2() {
	now := time.Now()
	timeStr := fmt.Sprintf("%02d-%02d-%02d  %02d:%02d:%02d \n ",
		now.Year(), now.Month(), now.Day(), now.Hour(), now.Minute(), now.Second())
	fmt.Printf("time :%s\n", timeStr)
}

func testCost() {
	start := time.Now().UnixNano() // 纳秒
	for i := 0; i < 10; i++ {
		time.Sleep(time.Millisecond)
	}
	end := time.Now().UnixNano()
	cost := (end - start) / 1000
	fmt.Printf("code cost:%d us\n", cost) //code cost:10000 us 大概10毫秒左右
}

func main() {
	//testTime()
	//timestamp := time.Now().Unix()
	//testTimestamp(timestamp)

	//testTicker() //定时器
	//testConst()

	testFormat()
	testFormat2()
	testCost()
}

输出:

01>>time :2022-03-12 18:29:36
02>>time :2022-3-12 18:29:36
03>>time :2022/03/12 18:29:36
04>>time :03/12/2022 18:29:36
05>>time :03/12/2022 6:29:36
time :2022-03-12  18:29:36

code cost:10000 us