The behavior of json.Unmarshal when encountering field type inconsistencies.

[ansionfor]

func TestJson(t *testing.T) {
    type info struct {
       Id int64 `json:"id"`
    }
    type test struct {
       Result []info `json:"result"`
    }
    r := `{"result":[{"id":"1"},{"id":"2"}]}`


    var res1 test
    var res2 test


    // use encoding/json
    json2.Unmarshal([]byte(r), &res1)

    // use json-iterator/go                 
    jsoniter.ConfigCompatibleWithStandardLibrary.Unmarshal([]byte(r), &res2)

    len1 := len(res1.Result)      // 2
    len2 := len(res2.Result)      // 1


    fmt.Println(len1, len2)
}

I want to know which handling behavior is more appropriate.

[Michailovich]

The appropriateness of the behavior depends on your specific use case and requirements:

Strict Type Checking (Standard encoding/json):

Pros: Ensures that the data conforms exactly to the expected types, which can prevent subtle bugs and data inconsistencies.
Cons: Requires the input data to be strictly formatted, which might not always be the case, especially when dealing with external APIs or user-generated content.
Lenient Type Conversion (json-iterator/go):

Pros: More flexible in handling input data, which can be useful when dealing with inconsistent or loosely typed JSON data.
Cons: May mask data issues and lead to unexpected behavior if the type conversion does not work as intended.

[hkb1990]

Both Unmarshal functions return Error. You should handle errors first. Otherwise results are unpredictable.

[ansionfor]

Thx guys