go中是否有一个atof等效项？

Question

When converting the string "3px" to a float, C is able to handle it but go does not. In go, is there a way to convert the longest valid prefix of a string to a float?

C:

#include <stdlib.h>
#include <stdio.h>

int main() { 
    printf("%f", atof("3px")); 
    // result: 3.0
    return 0;
}

Go:

package main

import "fmt"
import "strconv"

func main() {
    value, err := strconv.ParseFloat("3px", 64)
    fmt.Printf("%f, %v
", value, err)
    // strconv.ParseFloat: parsing "3px": invalid syntax
}

Answer 1

No, there is no way to convert the longest valid prefix of a string to a float. Value being converted should be valid. From Docs : If s is well-formed and near a valid floating point number, ParseFloat returns the nearest floating point number

https://golang.org/pkg/strconv/#ParseFloat

If you consider what C is doing, it is actually changing "3px" --> "3" first internally and then parsing. In Go, you have to explicitly strip out invalid chars before strconv can convert it.