看一段代碼先

package main

import (
    "strings"
    "fmt"
)

func shortenString(message string) func() string {
    return func() string {
        messageSlice := strings.Split(message, " ")
        wordLength := len(messageSlice)
        if wordLength < 1 {
            return "Nothing Left!"
        } else {
            messageSlice = messageSlice[:(wordLength - 1)]
            message = strings.Join(messageSlice, " ")
            return message
        }
    }
}

func main() {
    myString := shortenString("Welcome to concurrency in Go!...")
    fmt.Println(myString())
    fmt.Println(myString())
    fmt.Println(myString())
    fmt.Println(myString())
    fmt.Println(myString())
    fmt.Println(myString())
}

運行結(jié)果如下：
Welcome to concurrency in
Welcome to concurrency
Welcome to
Welcome

有沒有發(fā)現(xiàn)，多次運行同一個閉包函數(shù)，其修改的上層函數(shù)傳參值是同一個值