import "errors"
errors包实现了创建错误值的函数。
package errors_test import ( "fmt" "time" ) // MyError is an error implementation that includes a time and message. type MyError struct { When time.Time What string } func (e MyError) Error() string { return fmt.Sprintf("%v: %v", e.When, e.What) } func oops() error { return MyError{ time.Date(1989, 3, 15, 22, 30, 0, 0, time.UTC), "the file system has gone away", } } func Example() { if err := oops(); err != nil { fmt.Println(err) } // Output: 1989-03-15 22:30:00 +0000 UTC: the file system has gone away }
func New(text string) error
使用字符串创建一个错误,请类比fmt包的Errorf方法,差不多可以认为是New(fmt.Sprintf(...))。
err := errors.New("emit macho dwarf: elf header corrupted") if err != nil { fmt.Print(err) }
Output:
emit macho dwarf: elf header corrupted
const name, id = "bimmler", 17 err := fmt.Errorf("user %q (id %d) not found", name, id) if err != nil { fmt.Print(err) }
Output:
user "bimmler" (id 17) not found