解析嵌套的json对象golang

I want to parse mentioned json.

{"foo": [{ "bar": 1, "baz": 2 },{ "bar": 4, "baz": 25 }], "more": "text"}

using below struct to unmarshal

type FooStruct struct {
   Bar int `json:"bar"`
   Baz int `json:"baz"`
}

type  ResponseStruct struct {
    More string `json:"more"`
    Foo []FooStruct `json:"foo"`
}
var contentHtml ResponseStruct
err = json.Unmarshal(<byte_array>, &contentHtml)
fmt.Printf("%+v", contentHtml.FooStruct[0].Bar)

Your code is corrent, except this line:

fmt.Printf("%+v", contentHtml.FooStruct[0].Bar)

There is no fields FooStruct in ResponseStruct type. I think you need to use Foo instead.
Working example on the Go playground