go 集合

1.定义一个集合 感觉和python的字典差不多

func main() {
        //定义一个集合
        var countryCapitalMap map[string]string /*创建集合 */
        //创建集合
        countryCapitalMap = make(map[string]string)

        /* map插入key - value对,各个国家对应的首都 */
        countryCapitalMap["France"] = "Pais"
        countryCapitalMap["Italy"] = "罗马"
        countryCapitalMap["Japan"] = "东京"
        countryCapitalMap["India "] = "新德里"
        fmt.Println(countryCapitalMap)

}

2.循环输出key value

func main() {
    var countryCapitalMap map[string]string /*创建集合 */
    countryCapitalMap = make(map[string]string)

    /* map插入key - value对,各个国家对应的首都 */
    countryCapitalMap["France"] = "Paris"
    countryCapitalMap["Italy"] = "罗马"
    countryCapitalMap["Japan"] = "东京"
    countryCapitalMap["India "] = "新德里"

    for country := range countryCapitalMap {
        fmt.Println(country, countryCapitalMap[country])

    }
}

3.判断key是否存在

var countryCapitalMap map[string]string /*创建集合 */
        countryCapitalMap = make(map[string]string)

        /* map插入key - value对,各个国家对应的首都 */
        countryCapitalMap["France"] = "Paris"
        countryCapitalMap["Italy"] = "罗马"
        countryCapitalMap["Japan"] = "东京"
        countryCapitalMap["India "] = "新德里"
        //ok为bool值，为true那么captial就是这个key的value
        captial, ok := countryCapitalMap["Italy"]
        if ok {
                fmt.Println(ok, "存在首都是", captial)

        } else {

                fmt.Println("不存在")

        }

4.删除key value

   var countryCapitalMap map[string]string /*创建集合 */
    countryCapitalMap = make(map[string]string)

    /* map插入key - value对,各个国家对应的首都 */
    countryCapitalMap["France"] = "Paris"
    countryCapitalMap["Italy"] = "罗马"
    countryCapitalMap["Japan"] = "东京"
    countryCapitalMap["India "] = "新德里"
    delete(countryCapitalMap, "France")
    fmt.Println(countryCapitalMap)