lancet

https://github.com/duke-git/lancet

https://blog.csdn.net/weixin_41155794/article/details/122299637

https://zhuanlan.zhihu.com/p/543391872

去重并去空字符串和null值

lit.TargetHost = slice.Compact(slice.Unique(targetHosts))
slice.Sort(lit.TargetHost)


// SliceUniqueCompact 去重并过滤空客串
func SliceUniqueCompact(paramSlice []string) []string {
    if len(paramSlice) == 0 {
        return []string{}
    }
    return slice.Compact(slice.Unique(paramSlice))
}

只添加不存在的值到切片中

var names = make([]string, 0, total)
names = slice.AppendIfAbsent(names, "lisi")
names = slice.AppendIfAbsent(names, "lisi")
fmt.Println(result3)

// Output:
// ["lisi"]

RoundToFloat 四舍五入，保留n位小数

fNumb = mathutil.RoundToFloat(avgTmp, 4) //保留4位小数

函数签名:

func RoundToFloat(x float64, n int) float64
示例:

package main

import (
    "fmt"
    "github.com/duke-git/lancet/v2/mathutil"
)

func main() {
    result1 := mathutil.RoundToFloat(0.124, 2)
    result2 := mathutil.RoundToFloat(0.125, 2)
    result3 := mathutil.RoundToFloat(0.125, 3)

    fmt.Println(result1)
    fmt.Println(result2)
    fmt.Println(result3)

    // Output:
    // 0.12
    // 0.13
    // 0.125
}

RoundToString

四舍五入，保留n位小数，返回字符串

函数签名:

func RoundToString(x float64, n int) string

TruncRound

截短n位小数（不进行四舍五入）

函数签名:

func TruncRound(x float64, n int) float64

• 更多参考官网

百分比计算

a := 5
total := 10
proportion1 := fmt.Sprintf("%v%s", mathutil.Percent(float64(a), float64(total), 2), "%")
proportion := fmt.Sprintf("%.2f%s", mathutil.Percent(float64(a), float64(total), 2), "%")
fmt.Println("proportion1:", proportion1)
fmt.Println("proportion:", proportion)

// Output
// proportion1: 0.5%
// proportion: 0.50%

当月的开始时间

import "github.com/duke-git/lancet/v2/datetime"

input := time.Now().AddDate(-3, 0, 0) // 三年前
beginOfMonth := datetime.BeginOfMonth(input) //当月的开始时间 
endOfMonth := datetime.EndOfMonth(input)   //当月的结束时间 
fmt.Println("beginOfMonth:", beginOfMonth)
fmt.Println("endOfMonth:", endOfMonth)

// Output
// beginOfMonth: 2020-09-01 00:00:00
// endOfMonth: 2020-09-30 23:59:59