Go Lang - Last Task

The Size function currently returns just an int64 value representing a file size. Update it so that it returns both that int64 file size and an error value.

With Go, the function signature includes both the functions arguments and return value types. For example the function signature in this challenge takes a single argument of type string and returns a single value of type int64:

func Size(fileName string) int64 {}

Here's an example of a function signature that returns two types, first an int64 and also an error:

func Foo(name string) (int64, error) {}

The first step for this challenge is to update the function signature of the Size function to return two values, an int64 and an error, like in the example Foo function I listed above.

If the err return value from os.Stat is not nil, then Size should return a file size of 0 and whatever error value is in err.

To return multiple values in a Go function you simply write multiple values following the return keyword in a function. For example to return a an int64 and a string together you would write a return statement like this:

return 5, "foobar"

The challenge is asking you to write a return statement where it says // RETURN THE VALUES 0 AND err that returns both the number 0 and the error value assigned to the variable err. Currently you've written fmt.Println(err) here when instead you should be using a return statement that sends two values, the number 0 and err.

If the err value from os.Stat is nil, then Size should return the result of calling fileInfo.Size(), plus an error value of nil.

Lastly where the challenge says // RETURN THE VALUES fileInfo.Size() AND nil you need to write another return statement that returns two values like before. This time the return statement needs to send fileInfo.Size() as the first value and nil as the second. Here's an example of a return statement that sends the result of calling a method and a nil for the error value similar to what this challenge requires:

return foobar.Length(), nil

My examples here aren't exact answers so you'll need to adapt this to correctly pass the challenge. I hope that helps point you in the right direction, if this is still unclear try rewatching the Multiple Return Values video and feel free to ask for more clarity on what is unclear.

Cheers!