sync.Map取值

Question

ipTable类型是sync.Map，key全部是IP地址，value全部是true，长度未知，现在需要提取所有IP地址赋值给一个变量，每个IP以逗号间隔

Answer 1

package main

import (
    "fmt"
    "sync"
)

func main() {
    var ipTable sync.Map
    ipTable.Store("10.0.0.1", true)
    ipTable.Store("10.0.0.2", true)
    ipTable.Store("10.0.0.3", true)
    ipTable.Store("10.0.0.4", true)

    val := ""
    flag := true
    ipTable.Range(func(key, value interface{}) bool {
        if flag {
            flag = false
        } else {
            val += ","
        }
        val += key.(string)
        return true
    })
    fmt.Println(val)
}