GoError Handling


In Go, unexpected situations are handled using errors, not exceptions. This approach is more similar to that of C, using errno, than to that of Java or other object-oriented languages, with their try/catch blocks. However, an error is not an integer but an interface.

A function that may fail typically returns an error as its last return value. If this error is not nil, something went wrong, and the caller of the function should take action accordingly.


Note how in Go you don't raise an error. Instead, you return an error in case of failure.

If a function can fail, the last returned value is generally an error type.

// This method doesn't fail
func DoSomethingSafe() {

// This method can fail
func DoSomething() (error) {

// This method can fail and, when it succeeds,
// it returns a string.
func DoAndReturnSomething() (string, error) {