Go : When will json.Unmarshal to struct return error?

Question

Assume i have a struct like

type A struct{
  name string`json:\"name\"`
}

Then in main i have code

var jsonString string =          


        

Answer 1

To add to icza's answer, you can also get an error if you try to Unmarshal into a typed nil pointer. This can happen if, for example, you make a slice of pointers to a particular type, then try and unmarshal into a particular one of those pointers.

package main

import (
    "fmt"
    "encoding/json"
)

type Example struct {Name string}


func main() {
        exs := make([]*Example, 5)
        err := json.Unmarshal([]byte(`{"name":"jane"}`), exs[0])
        fmt.Println(err)
}
// json: Unmarshal(nil *main.Example)