go - 如何在编码而不是 json 时出错

Question

我有一张 map ，其字符串和值的键是一个接口(interface)。我将一些键和值放入该映射中，我想对其进行编码，但我想获得“无效”，或者我希望我的编码出现错误？为了成功，我需要在该 map 中放入什么样的变量？

myBlobMap := make(map[string]interface{})
blobmap["firstKey"] = "firstValue"
blobmap["secondKey"] = "secondValue"
jsonByte, err := json.Marshal(myBlobMap)

Answer 1

来自 Go documentation on json :

Channel, complex, and function values cannot be encoded in JSON.Attempting to encode such a value causes Marshal to return anUnsupportedTypeError.

JSON cannot represent cyclic data structures and Marshal does nothandle them. Passing cyclic structures to Marshal will result in anerror.

这是一个带有将返回错误的函数的示例:

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    myBlobMap := make(map[string]interface{})
    myBlobMap["firstKey"] = func() {}
    myBlobMap["secondKey"] = "secondValue"
    jsonByte, err := json.Marshal(myBlobMap)
    fmt.Print(jsonByte, err)
}

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