go Language Interface Type assertion resolve

1 Type assertion

Writing: x (T)..
x: a need to assert the interface type, T: assertion types.
For: determining the port T x satisfies the query contains the T x of the interface.

2 determines whether a variable implements the specified interface

example:

if err,ok :=x.(error); ok {
	return err.Error()
}

3 types of conversions

Definition: If we want to reverse this interface variables ⾥ ⾯ know the actual storage is the type of the object which can be recorded using the following ⽅ be performed because the conversion

    var t int
    var x interface{}
    x = t
    y, ok = x.(int) //转成int，带检查

Gets the type 4

func justify(items ...interface{}) {
	for index, v := range items {
		switch v.(type) {
		case int:
			fmt.Printf("第 %d 个参数 is int\n", index)
		case int32:
			fmt.Printf("第 %d 个参数 is int32\n", index)
		case float32:
			fmt.Printf("第 %d 个参数 is float32\n", index)
		
		}
	}
}

func main(){
	var a int
	var b float32
	var c int32
	justify(a, b, c)
}