无法将函数声明为golang中主函数之外的变量

是有效的例子

package main

import "fmt"

func main() {
    var newFunc func(int, int) int
    newFunc = func(i int, j int) int {
        return (i * j)
    }

    fmt.Println(newFunc(10, 20))

}

package main

import "fmt"

var newFunc func(int, int) int
newFunc = func(i int, j int) int {
    return (i * j)
}

func main() {


    fmt.Println(newFunc(10, 20))

}

编译错误详细信息如下:

.\functionanonymous1.go:6:1: syntax error: non-declaration statement outside function body
.\functionanonymous1.go:6:15: missing function body
.\functionanonymous1.go:6:33: method has multiple receivers
.\functionanonymous1.go:7:2: syntax error: unexpected return, expecting )
.\functionanonymous1.go:8:1: syntax error: non-declaration statement outside function body