http：紧急服务[:: 1]：57685：分配给零图中的条目

Question

I am trying to make a vcard using golang.My code is:

    var (
    // card is a map of strings to []*vcard.Field objects
    card vcard.Card

    // destination where the vcard will be encoded to
    enc = vcard.NewEncoder(destFile) 
)
var str []string


for i, entry := range k {


    if i!=2{
        str=append(str,k[i])


        card.SetValue(vcard.FieldFormattedName, strings.Join(str[:i],""))//panic occurs here
        fmt.Println(str)

    }else if i==2{
        card.SetValue(vcard.FieldTelephone, entry)
    }else{
        card.SetValue(vcard.FieldOrganization, entry)
    }




    // set the value of a field and other parameters by using card.Set
    card.Set(vcard.FieldName, &vcard.Field{
        Value: strings.Join(str[:2], ";"),
        Params: map[string][]string{
            vcard.ParamSortAs: []string{
                k[0] + " " + k[1],
            },
        },
    })

The json document which has to be stored in vcf is:

      {"firstname":"Vilas","lastname":"Prakash","mobile":"8732647482","organisation":"Dbjb"}

I have marshalled the json to []string.On executing I am getting the following error:

    http: panic serving [::1]:57685: assignment to entry in nil map

Can anyone help me???Or Is there any other way of creating .vcf or vcard in golang using json document as input???

Answer 1

You haven't initialized your map. I suggest you read up on how maps work in Go https://blog.golang.org/go-maps-in-action

In the meantime

var card vcard.Card

should be

var card = make(vcard.Card)

I'm not familiar with the vcard data structure. But you mention that it should be a map -> string][]*vcard.Field.. If the above make fails change it to

var card = make(map[string][]*vcard.Field)