什么时候在Go中使用var或：=？ [重复]

Question

This question already has an answer here:

• Why there are two ways of declaring variables in Go, what's the difference and which to use? 1 answer
• var vs := in Go 3 answers

Is there any difference between the following two examples?

type Example struct {}

func main() {
  e := Example{}
}

vs.

type Example struct {}

func main() {
  var e Example
}

Is there a preferable one?

Thanks!

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Answer 1

Might worth noting:

Use := when you need to create a variable with a defined value on it.

number := 12
obj := SomeStruct{name: "user"}
slice := []string{"a", "b", "c"}

---

Use var keyword when you need to define a variable without any initialisation, so the zero value will be used on it.

var a int // the default value will be the zero value of int, which is 0
var mut sync.Mutex
var result []map[string]interface{}

Also there is another advantage of using var keyword, like we can create multiple variable with one type in one line.

var result1, result2, result3, result4 []map[string]interface{}