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Golang 错误及错误处理
错误捕获
package main
import (
"errors"
"fmt"
)
func f1(arg int) (int, error) {
if arg == 42 {
return -1, errors.New("can't work with 42")
}
return arg + 3, nil
}
type argError struct {
arg int
prob string
}
func (e *argError) Error() string {
return fmt.Sprintf("%d - %s", e.arg, e.prob)
}
func f2(arg int) (int, error) {
if arg == 42 {
return -1, &argError{arg, "can't work with it"}
}
return arg + 3, nil
}
func main() {
for _, i := range []int{7, 42} {
if r, e := f1(i); e != nil {
fmt.Println("f1 failed:", e)
} else {
fmt.Println("f1 worked:", r)
}
}
for _, i := range []int{7, 42} {
if r, e := f2(i); e != nil {
fmt.Println("f2 failed:", e)
} else {
fmt.Println("f2 worked:", r)
}
}
_, e := f2(42)
if ae, ok := e.(*argError); ok {
fmt.Println(ae.arg)
fmt.Println(ae.prob)
}
}
package main
import (
"errors"
"fmt"
)
func f1(arg int) (int, error) {
if arg == 42 {
return -1, errors.New("can't work with 42")
}
return arg + 3, nil
}
type argError struct {
arg int
prob string
}
func (e *argError) Error() string {
return fmt.Sprintf("%d - %s", e.arg, e.prob)
}
func f2(arg int) (int, error) {
if arg == 42 {
return -1, &argError{arg, "can't work with it"}
}
return arg + 3, nil
}
func main() {
for _, i := range []int{7, 42} {
if r, e := f1(i); e != nil {
fmt.Println("f1 failed:", e)
} else {
fmt.Println("f1 worked:", r)
}
}
for _, i := range []int{7, 42} {
if r, e := f2(i); e != nil {
fmt.Println("f2 failed:", e)
} else {
fmt.Println("f2 worked:", r)
}
}
_, e := f2(42)
if ae, ok := e.(*argError); ok {
fmt.Println(ae.arg)
fmt.Println(ae.prob)
}
}
运行：
$ go run errors.go
f1 worked: 10
f1 failed: can't work with 42
f2 worked: 10
f2 failed: 42 - can't work with it
42
can't work with it
$ go run errors.go
f1 worked: 10
f1 failed: can't work with 42
f2 worked: 10
f2 failed: 42 - can't work with it
42
can't work with it
错误处理
创建error：
func main() {
defer func() {
if err := recover(); err != nil {
fmt.Println(err)
}
}()
fmt.Println("main() started")
panic("error here.")
fmt.Println("END main()")
}
func main() {
defer func() {
if err := recover(); err != nil {
fmt.Println(err)
}
}()
fmt.Println("main() started")
panic("error here.")
fmt.Println("END main()")
}
参考链接
- err handling go blog: https://go.dev/blog/error-handling-and-go