如何重置地图地图中的值

Question

这是我的代码{    saruman := map[string]int{     "power": 150,     "skills": 200,     "knowledge": 380,    }    gandalf := map[string]int{     "power": 180,     "skills": 210,     "knowledge": 240,    }    wizards := make(map[string]interface{})    wizards["saruman"] = saruman    wizards["gandalf"] = gandalf    fmt.Println(wizards)    //OK map[gandalf:map[knowledge:240 power:180 skills:210] saruman:map[knowledge:380 power:150 skills:200]]    //change gandalf property    wizards["gandalf"]["knowledge"] = 310    fmt.Println(wizards)}在最后一行，我们得到：NOK无效操作：wizards["gandalf"]["knowledge"]（类型接口{}不支持索引）

Answer 1

您不能使用它["key"]来访问 golang 不知道的结构。因为它是interface{}甘道夫背后的价值，可以是任何东西。

    wizards["gandalf"] = map[string]int{
             "knowledge": 310,
    }

您必须指定要与之交互的数据类型。

游乐场：https ://goplay.tools/snippet/O62ara8JbUv

Answer 2

这是更简单的方法：

一行代码

wizards["gandalf"].(map[string]int)["knowledge"] = 110

完整示例：

saruman := map[string]int{

    "power":     150,

    "skills":    200,

    "knowledge": 380,

}

gandalf := map[string]int{

    "power":     180,

    "skills":    210,

    "knowledge": 240,

}

wizards := make(map[string]interface{})

wizards["saruman"] = saruman

wizards["gandalf"] = gandalf

// fmt.Println(wizards)

// OK map[gandalf:map[knowledge:240 power:180 skills:210] saruman:map[knowledge:380 power:150 skills:200]]

// change gandalf property

wizards["gandalf"].(map[string]int)["knowledge"] = 110

fmt.Println(wizards["gandalf"].(map[string]int)["knowledge"])

Answer 3

需要投。

{

    saruman := map[string]int{

        "power":     150,

        "skills":    200,

        "knowledge": 380,

    }

    gandalf := map[string]int{

        "power":     180,

        "skills":    210,

        "knowledge": 240,

    }

    wizards := make(map[string]interface{})

    wizards["saruman"] = saruman

    wizards["gandalf"] = gandalf

    fmt.Println(wizards)

    //OK map[gandalf:map[knowledge:240 power:180 skills:210] saruman:map[knowledge:380 power:150 skills:200]]

    //change gandalf property

    wizards["gandalf"].(map[string]int)["knowledge"] = 10

    fmt.Println(wizards)

}