Testing for Errors on Functions

Sometimes, functions in Go are defined so that they return two results. One is the value and the other is the status of the execution. For example, the function will return a value and true in case of successful execution. Whereas, it will return a value (probably nil) and false in case of an unsuccessful execution.

Instead of true and false, an error-variable can be returned. In the case of successful execution, the error is nil. Otherwise, it contains the error information. It is then obvious to test the execution with an if statement because of its notation; this is often called the comma, ok pattern.