Golang结构体指针应用 嵌套指针字段访问

.

type Person struct {
    Name string
    Age  int
}

p := &Person{Name: "Alice", Age: 30}
fmt.Println(p.Name) // 直接访问，等价于 (*p).Name

type Address struct {
    City  string
    Zip   string
}

type Person struct {
    Name    string
    Address *Address // 指向Address的指针
}

p := &Person{Name: "Bob"}
// 错误：p.Address 为 nil，直接访问会 panic
// fmt.Println(p.Address.City)

// 正确做法：先初始化
p.Address = &Address{City: "New York", Zip: "10001"}
fmt.Println(p.Address.City) // 输出: New York

**Address

type Person struct {
    Name       string
    AddrPtrPtr **Address
}

addr := &Address{City: "Seattle"}
addrPtr := &addr
p := &Person{Name: "Carol", AddrPtrPtr: addrPtr}

// 多层解引用前需确保每层非nil
if p.AddrPtrPtr != nil && *p.AddrPtrPtr != nil {
    fmt.Println((*p.AddrPtrPtr).City)
}

func (p *Person) SetCity(city string) {
    if p.Address == nil {
        p.Address = &Address{}
    }
    p.Address.City = city
}

p.SetCity("Boston")