在Go语言中，结构体（struct）是一种聚合的数据类型，它可以包含多个不同的数据类型，包括其他结构体。当你在一个结构体中嵌套另一个结构体时，你可以像访问普通字段一样访问嵌套结构体的字段。
定义结构体：首先，你需要定义两个或更多的结构体类型。其中一个结构体可以包含另一个结构体作为其字段。
创建实例：然后，你可以创建包含嵌套结构体的实例。
访问字段：要访问嵌套结构体的字段，你需要通过外部结构体的实例来逐步访问到嵌套结构体的字段。这通常通过链式访问（点操作符.）来实现。
1 | type Inner struct { |
这里，outer是Outer类型的实例，Inner是Outer结构体中的一个字段，它本身是一个Inner类型的实例，而A是Inner结构体中的字段。通过点操作符.，你可以从一个结构体实例中访问另一个结构体实例的字段，即使它们是嵌套的。
结构体嵌套时字段访问的原理就是通过点操作符.来链式访问嵌套结构体的字段，这使得你可以访问任意深度的嵌套结构体字段。
Analysis of the principle of accessing structure nested fields in Go language
In Go, a struct is an aggregated data type that can contain multiple different data types, including other structs. When you nest another structure in one structure, you can access the fields of the nested structure just like you would access the normal fields.
Definition Structure: First, you need to define two or more structure types. One of the structures may contain another structure as its field.
Create instance: You can then create an instance containing a nested structure.
Access Field: To access the fields of a nested structure, you need to gradually access the fields of the nested structure through an instance of the external structure. This is usually achieved through chain access (dot operator .).
1 | type Inner struct { |
Here, outer is an instance of the Outer type, Inner is a field in the Outer structure, which itself is an instance of the Inner type, and A is a field in the Inner structure. With the dot operator ., you can access fields from one struct instance, even if they are nested.
The principle of field access when structs are nested is to access the fields of nested structures in a chain through the point operator ., which allows you to access nested structure fields of any depth.