Created
January 18, 2018 22:02
-
-
Save c-yan/75add7f328181e76bf72b3dfa249ace4 to your computer and use it in GitHub Desktop.
[A Tour of Go] Exercise: Errors
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
package main | |
import ( | |
"fmt" | |
) | |
type ErrNegativeSqrt float64 | |
func (e ErrNegativeSqrt) Error() string { | |
return fmt.Sprintf("cannot Sqrt negative number: %v", float64(e)) | |
} | |
func Sqrt(x float64) (float64, error) { | |
if x < 0 { | |
return 0, ErrNegativeSqrt(x) | |
} | |
z := 1.0 | |
for i := 0; i < 10; i++ { | |
z = z - (z*z-x)/(2*z) | |
} | |
return z, nil | |
} | |
func main() { | |
fmt.Println(Sqrt(2)) | |
fmt.Println(Sqrt(-2)) | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment