如何在 Golang 函数中处理错误

func divide(x, y int) (int, error) {
  if y == 0 {
    return 0, errors.New("cannot divide by zero")
  }
  return x / y, nil
}

func checkError(err error) bool {
  var myErr *MyError
  if errors.As(err, &myErr) {
    // err 是 *MyError 类型
    return true
  }
  return false
}

func checkEOF(err error) bool {
  return errors.Is(err, io.EOF)
}

import (
  "errors"
  "fmt"
  "io/ioutil"
)

func readFile(path string) (string, error) {
  data, err := ioutil.ReadFile(path)
  if err != nil {
    switch {
      case errors.Is(err, os.ErrNotExist):
        return "", fmt.Errorf("file not found: %v", path)
      case errors.Is(err, os.ErrPermission):
        return "", fmt.Errorf("permission denied: %v", path)
      default:
        return "", fmt.Errorf("failed to read file: %v", err)
    }
  }
  return string(data), nil
}

result, err := readFile("/path/to/file")
if err != nil {
  fmt.Println(err)
} else {
  fmt.Println(result)
}