Invalid json will be unmarshal into a wrong result without throw error

[dayeguilaiye]

I have a struct like below:

{
	"classroom": {
		"students": [
			"name": John,
			"scores": A,
		]
	}
}

The content in students is wrong, it missed a {} to wrap the name and score, which cause this string is not actually a valid json string.

but when I unmarshal with yaml.Unmarshal, no error is returned, and the result seem very weird. This is a simple example to reproduce:

type Student struct {
	Name   string `json:"name"`
	Scores string `json:"scores"`
}

type Classroom struct {
	Students []Student `json:"students"`
}

type School struct {
	Classroom Classroom `json:"classroom"`
}

func TestName(t *testing.T) {
	wrongInput := `{
	"classroom": {
		"students": [
			"name": John,
			"scores": A,
		]
	}
}`
	c := new(School)
	err := yaml.Unmarshal([]byte(wrongInput), c)
	fmt.Println(err)
	fmt.Printf("%+v", c)
}

output is:

<nil>
&{Classroom:{Students:[{Name:John Scores:} {Name: Scores:A}]}}

The result is there are two students in this classroom.

The most important question is why there is no error returned?