将两个返回值传递给具有一个参数的函数

Question

I want to do this:

R, _ := strconv.Atoi(reader.ReadString(" ")) // reader = bufio.NewReader()

and the problem is, that strconv.Atoi expects one argument, but reader.ReadString() returns not only the string, but also the "err". Is there a way to solve this without creating variables or generally on just one line?

Answer 1

In Go, write a readInt function to hide the complexity and always check for errors. Other answers have bugs: Howl (drops last number) and Raduan Santos (doesn't compile).

For example,

package main

import (
    "bufio"
    "fmt"
    "io"
    "log"
    "strconv"
    "strings"
)

func readInt(r *bufio.Reader) (int, error) {
    const delim = ' '
    str, err := r.ReadString(delim)
    if err != nil && len(str) == 0 {
        return 0, err
    }
    str = strings.TrimSuffix(str, string(delim))
    return strconv.Atoi(str)
}

func main() {
    input := "93 31 11 11"
    fmt.Println(input)
    rdr := bufio.NewReader(strings.NewReader(input))
    for {
        n, err := readInt(rdr)
        if err != nil {
            if err == io.EOF {
                break
            }
            log.Fatal(err)
        }
        fmt.Println(n)
    }
}

Output:

93 31 11 11
93
31
11
11