GO err is shadowed during return

这里先复现问题，然后进行问题说明。

//test.go

package mainimport "fmt"import "strconv"func foo(x string) (ret int, err error) {	if true {		ret, err := strconv.Atoi(x)		if err != nil {			return		}	}	return ret, nil}func main() {	fmt.PRintln(foo("123"))}
运行：
OK，问题复现了，下面进行问题分析。
func foo(x string) (ret int, err error) {//返回值列表定义了ret和err变量，作用域是整个函数体if true {//新的语句块ret, err := strconv.Atoi(x)  //这里又定义了新的变量ret和err，和返回值列表重名了。作用域是if语句块if err != nil {return  //这里的return语句会导致外层的ret和err被返回，而不是if语句里的ret和err}}return ret, nil}
来自网上的解释：
It's a new scope, so a naked return returns the outer err, not your inner err that was != nil.So it's almost certainly not what you meant, hence the error.下面进行修改（只需要保证局部变量和全局变量不重名即可）:
//test.go
package mainimport "fmt"import "strconv"func foo(x string) (ret int, err error) {if true {ret1, err1 := strconv.Atoi(x)if err1 != nil {err = err1return}ret = ret1}return ret, nil}func main() {fmt.Println(foo("123"))}
运行：