the-way-to-go_ZH_CN/eBook/examples/chapter_10/method2.go

package main

import "fmt"

type IntVector []int

func (v IntVector) Sum() (s int) {
	for _, x := range v {
		s += x
	}
	return
}

func main() {
	fmt.Println(IntVector{1, 2, 3}.Sum()) // Output: 6
}