How can we truncate float64 type to a particular precision?

Question

package main

import (
    \"fmt\"
    \"strconv\"
    )

func main() {
    k := 10/3.0
    i := fmt.Sprintf(\"%.2f\", k)
    f,_ := strconv.ParseFloat(i, 2)
    fmt.Pri         


        

Answer 1

So after much hunting around, coming to this thread multiple times I finally found a very simple solution that allows you to control the precision of floats very simply without any weird math!

package main

import (
    "fmt"
    "github.com/shopspring/decimal"
)

func main() {
    k := 101.3874927181298723478
    p := 5

    v := decimal.NewFromFloat(k).Round(int32(p))
    fmt.Println(v)
}
// 101.38749

Source: https://godoc.org/github.com/shopspring/decimal#Decimal.Round

While I like some of the simple methods like "%.3f\n", k options, these produced a string that I would then have to convert back into a float with another strconv command that I didn't want to do.