GoKawiilError handling Introduction to error handling strategies in Go
Go's approach to error handling is based on two ideas:
Errors are an important part of an application's or library’s interface.
Failure is just one of several expected behaviors.
Thus, errors are values, just like any other values returned by a function. You should therefore pay close attention to how you create and handle them.
Some functions, like strings.Contains or strconv.FormatBool , can never fail. If a function can fail, it should return an additional value. If there's only one possible cause of failure, this value is a boolean:
value , ok := cache . Lookup ( key ) if ! ok { // key not found in cache }
If the failure can have multiple causes, the return value is of type error :
f , err := os . Open ( "/path/to/file" ) if err != nil { return nil , err }
The simplest way to create an error is by using fmt.Errorf (or errors.New if no formatting is needed):
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