[go学习笔记]十六、如何编写好的错误处理机制

Go的错误机制

• 没有异常机制
• error类型实现了error接口

type error interface {
    Error() string
}

• 可以通过 errors.New来快速创建错误实例

errors.New("n must be in the range [0,10]")

示例代码

package err_test

import (
	"fmt"
	"github.com/pkg/errors"
	"testing"
)

var LessThanTwoError = errors.New("n should be not less than 2")

var LargerhanHundredError = errors.New("n should be not less than 2")

func GetFibonaccin(n int) ([]int, error) {
	if n < 2 {
		return nil, LessThanTwoError
	}
	if n > 100 {
		return nil, LargerhanHundredError
	}
	fibList := []int{1, 1}
	for i := 2; i < n; i++ {
		fibList = append(fibList, fibList[i-2]+fibList[i-1])
	}
	return fibList, nil
}

func TestGetFibonaccin(t *testing.T) {
	if v, err := GetFibonaccin(1); err != nil {
		if err == LessThanTwoError {
			fmt.Println("It is less")
		}
		if err == LargerhanHundredError {

		}
		t.Log(err)
	} else {
		t.Log(v)
	}

}

输出

=== RUN   TestGetFibonaccin
It is less
--- PASS: TestGetFibonaccin (0.00s)
    error_test.go:35: n should be not less than 2
PASS

Process finished with exit code 0

最佳实践

func GetFibonacci1(str string) {
	var (
		i    int
		err  error
		list []int
	)
	if i, err = strconv.Atoi(str); err == nil {
		if list, err = GetFibonacci(i); err == nil {
			fmt.Println(list)
		} else {
			fmt.Println("Error", err)
		}
	} else {
		fmt.Println("Error", err)
	}
}

func GetFibonacci2(str string) {
	var (
		i    int
		err  error
		list []int
	)
	if i, err = strconv.Atoi(str); err != nil {
		fmt.Println("Error", err)
		return
	}

	if list, err = GetFibonacci(i); err != nil {
		fmt.Println("Error", err)
		return
	}
	fmt.Println(list)
}