何时使用指向嵌套结构的JSON指针？ [重复]

Question

This question already has an answer here:

• Pointers vs. values in parameters and return values 3 answers
• What's the difference between pointer and value in struct? 2 answers
• memory efficient way 1 answer

EDIT: I feel this question is not a duplicate, as the referenced Q&A do not describe JSON in the use cases.

I have a struct nested within another struct that I use for JSON operations.

In a simple test case, using a copy of a nested struct:

type A struct {
    Foo string
    Bar B
}

type B struct {
    Baz string
}

func main() {
    serialized := `{"foo": "some", "bar": {"baz": "thing"}}`
    a := &A{}
    json.Unmarshal([]byte(serialized), a)
    fmt.Println(a.Foo, a.Bar.Baz)
}
> some thing

yields the same results as using a pointer to a nested struct:

type A struct {
    Foo string
    Bar *B
}

type B struct {
    Baz string
}

func main() {
    serialized := `{"foo": "some", "bar": {"baz": "thing"}}`
    a := &A{}
    json.Unmarshal([]byte(serialized), a)
    fmt.Println(a.Foo, a.Bar.Baz)
}
> some thing

When would or would I not want to use a pointer?

</div>