GO Structs and Methods 3

Question 1

What is the correct way to call a method `Greet()` on a pointer to a struct `p *Person`?

Accepted Answer

p.Greet()

Answer

(*p).Greet() only — automatic dereferencing does not apply to methods

Answer

p->Greet()

Answer

Person.Greet(p)

Question 2

Which of the following struct definitions is valid Go syntax?

Accepted Answer

type Employee struct { Name string; Salary float64; Manager *Employee }

Answer

struct Employee { Name string, Salary float64 }

Answer

type Employee = { Name: string; Salary: float64 }

Answer

define Employee struct { Name string | Salary float64 }

Question 3

What is the zero value of a struct field of type `*int` in Go?

Accepted Answer

nil

Answer

0

Answer

A pointer to a zero-valued int

Answer

undefined

Question 4

How does Go handle method sets for a value type `T` versus a pointer type `*T`?

Accepted Answer

Value type T can only call value receiver methods; pointer type *T can call both value and pointer receiver methods

Answer

Both T and *T have identical method sets

Answer

Pointer type *T can only call pointer receiver methods

Answer

Value type T can call pointer receiver methods but not vice versa

Question 5

What is the purpose of using `new(T)` versus `&T{}` when creating a struct in Go?

Accepted Answer

Both allocate a zeroed struct and return a pointer; `&T{}` also lets you set initial field values

Answer

`new(T)` allocates on the stack; `&T{}` always allocates on the heap

Answer

`new(T)` returns a value; `&T{}` returns a pointer

Answer

`new(T)` can only be used with primitive types, not structs

Question 6

In the following code, what does the embedded type enable?
```go
type Animal struct{ Name string }
func (a Animal) Speak() string { return a.Name }
type Dog struct{ Animal; Breed string }
d := Dog{Animal: Animal{"Rex"}, Breed: "Lab"}
fmt.Println(d.Speak())
```

Accepted Answer

Calling `d.Speak()` directly without qualifying it as `d.Animal.Speak()`

Answer

Dog inherits Animal's data but not its methods

Answer

Only `d.Animal.Speak()` works; promotion does not apply here

Answer

A compilation error because Dog embeds a non-interface type

Question 7

What does the `json:"name,omitempty"` struct tag do when using `encoding/json`?

Accepted Answer

Serializes the field as 'name' in JSON and omits it entirely if it has the zero value

Answer

Marks the field as read-only during JSON deserialization

Answer

Encodes the field only when it is explicitly set to nil

Answer

Renames the field to 'omitempty' and uses 'name' as a secondary key