Golang with interface{} to receive any parameters and strong turn

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In the function's pass-through value, interface{} can be passed arbitrary arguments, just like the Java object.
Here's the first time I've taken it for granted. * * ERROR code

package mainfunc main() {    Any(2)    Any("666")}func Any(v interface{})  {     v1:=int(v)     println(v1)    }

I just want it to be compiled, because the error code above does not have any syntax errors, only 666 to say, the following is the compiler error prompt:
Cannot convert V (type interface {}) to type Int:need type assertion
The correct code will ensure that the program does not make any mistakes.

package mainfunc main() {    Any(2)    Any("666")}func Any(v interface{})  {    if v2, ok := v.(string);ok{        println(v2)    }else if v3,ok2:=v.(int);ok2{        println(v3)    }}

The output is as follows

2666

Have to marvel at the rigor of go. Java writes a similar code and then it's gone.

Invisible I sprayed a lot of Java, but it is 20 years ago the language, older than me, some problems are really no way, now based on the JVM Kotlin, if I did not give up Android, I think I now the main working language is it.

Explain why Golang some cases, strong turn can, a little case, strong turn can not:
In fact, stack overflow a foreign great God said very well,
Exact words + wild translation

The reason why cannot convert an interface typed value is these rules in the referenced specs parts:
Conversions is expressions of the form T (x) where T was a type and x is an expression, that can being converted to type T.
A non-constant value X can is converted to type T in any of these cases:

• X is assignable to T.
• X ' s type and T have identical underlying types.
• X ' s type and T is unnamed pointer types and their pointer base types have identical underlying types.
• X's type and T is both integer or floating point types.
• X ' s type and T are both complex types.
• X is an integer or a slice of bytes or runes and T is a string type.
• X is a string and T is a slice of bytes or runes.
  But
  iAreaId := int(val)Is isn't any of the cases 1.-7.

Address: About interface{} as a parameter

The wild translations are as follows:
I am too lazy to turn over ....