不能在函数参数中使用document [0]（uint8类型）作为[] byte类型

Question

I'm trying to get a JSON string pulled from a document and into SimpleJson in GOlang, though I've run into a problem with the types (again..)

I get the following error:

cannot use document[0] (type uint8) as type []byte in function argument

and the line which bugs up is:

js, err := simplejson.NewJson(document[0])

Could anyone please help me fix this, and also is there a good place I can read up about types and conversions? Having come from php which has no types and python where the conversions are simple, GO is a bit confusing on this front.

Thanks :-)

Answer 1

First of all, uint8 is simply an alias for byte. Therefor []uint8 is the same as []byte.

What the error message tells you is that document[0] is of type uint8 and not []byte

From your comment it is clear that document is a string. You should just convert it to []byte. If the JSON data in itself contains an array, you must first parse the document (pass it to NewJson) before you can retrieve the first value of the JSON array.

So, instead change your code to:

js, err := simplejson.NewJson([]byte(document))
// error testing
jsonArray, err := js.Array()
// more error testing
fmt.Println(jsonArray[0])

(I assume you have imported the github.com/xiocode/toolkit/simplejson package. The only one I could find with simplejson.NewJson)