去提供可变消毒吗？

Question

I am a beginner in Golang. I have a problem with variable type assigning from user input.

When the user enters data like "2012BV352" I need to be able to ignore the BV and pass 2012352 to my next function.

There has a package name gopkg.in/validator.v2 in doc

But what it returns is whether or not the variable is safe or not.

I need to cut off the unusual things.

Any idea on how to achieve this?

Answer 1

You could write your own sanitizing methods and if it becomes something you'll be using more often, I'd package it out and add other methods to cover more use cases.

I provide two different ways to achieve the same result. One is commented out.

I haven't run any benchmarks so i couldn't tell you for certain which is more performant, but you could write your own tests if you wanted to figure it out. It would also expose another important aspect of Go and in my opinion one of it's more powerful tools... testing.

package main

import (
    "fmt"
    "log"
    "regexp"
    "strconv"
    "strings"
)
// using a regex here which simply targets all digits and ignores everything else.  I make it a global var and use MustCompile because the
// regex doesn't need to be created every time.
var extractInts = regexp.MustCompile(`\d+`)

func SanitizeStringToInt(input string) (int, error) {
    m := extractInts.FindAllString(input, -1)
    s := strings.Join(m, "")
    return strconv.Atoi(s)
}


/*

// if you didn't want to use regex you could use a for loop
func SanitizeStringToInt(input string) (int, error) {
    var s string
    for _, r := range input {
        if !unicode.IsLetter(r) {
            s += string(r)
        }
    }

    return strconv.Atoi(s)
}

*/


func main() {
    a := "2012BV352"
    n, err := SanitizeStringToInt(a)
    if err != nil {
        log.Fatal(err)
    }
    fmt.Println(n)
}