编辑代码

package main
import (
    "fmt"
    "strings"
    "strconv"
)

func WriteAmountStrToBuilder(b *strings.Builder, amount int64) {
    integral := amount / 100
    fraction := amount % 100

    b.WriteString(strconv.FormatInt(integral, 10))
    if fraction != 0 {
        b.WriteString(".")
        b.WriteString(strings.TrimRight(strconv.FormatInt(fraction, 10), "0"))
    }
}

func main () {
    //JSRUN引擎2.0,支持多达30种语言在线运行,全仿真在线交互输入输出。
    //fmt.Println("Hello JSRUN!   \n\n         - from Golang .")
    // aa := strings.TrimRight("00", "0")
    // fmt.Println(aa == "")

    // fmt.Println(strings.TrimRight("00", "0"))
    // fmt.Println(strings.TrimRight("20", "0"))
    // fmt.Println(strings.TrimRight("020", "0"))
    // fmt.Println(strings.TrimRight("20.00", "0"))

    var b strings.Builder
    b.WriteString("已使用")
    WriteAmountStrToBuilder(&b, 2054)
    b.WriteString("元优惠券,超过金额不予退还")
    fmt.Println(b.String())
}