go语言学习之 闭包函数

package main
import "fmt"
func main() {
	res :=adder()
	for i := 0; i < 5; i++ {
		fmt.Println("%d =",i)
		fmt.Println(res(i))
	}

}

func adder() func(int) int{
	sum := 0
	res := func(num int) int{
		sum += num
		return sum
	}
	return res
}