Pointer receivers in Go - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a pointer receiver in Go?

A pointer receiver is a method receiver that uses a pointer to the type, allowing the method to modify the original value the pointer points to.

beginner

Why use pointer receivers instead of value receivers?

Pointer receivers allow methods to modify the original struct, avoid copying large structs, and maintain consistency when some methods need to modify the receiver.

beginner

How do you declare a method with a pointer receiver in Go?

Use a receiver with a pointer type, for example:

func (p *Person) UpdateName(newName string) { p.Name = newName }

intermediate

What happens if you call a pointer receiver method on a value?

Go automatically takes the address of the value to call the pointer receiver method, so it works seamlessly without explicit pointers.

intermediate

Can pointer receivers be used with interfaces?

Yes, but only if the interface variable holds a pointer to the type. Methods with pointer receivers require the value to be a pointer to satisfy the interface.

What is the main benefit of using a pointer receiver in Go methods?

A It prevents the method from modifying the struct.

B It allows the method to modify the original struct.

C It makes the method run faster by default.

D It automatically copies the struct before method call.

Pointer receivers let methods change the original struct by using its memory address.

How do you declare a pointer receiver method for a struct named Car?

A func (c *Car) Drive() {}

B func Drive(c *Car) {}

C func Drive(c Car) {}

D func (c Car) Drive() {}

Pointer receiver methods use a pointer in the receiver: (c *Car).

If you have a value of type Person, can you call a method with a pointer receiver on it?

A Only if the method does not modify the struct.

B No, you must use a pointer explicitly.

C Yes, Go automatically takes the address.

D Only if the struct is small.

Go automatically converts the value to a pointer when calling pointer receiver methods.

Which of these is true about interfaces and pointer receivers?

A Only pointer types can satisfy interfaces with pointer receiver methods.

B A value type can satisfy an interface with pointer receiver methods.

C Interfaces cannot have pointer receiver methods.

D Pointer receivers are ignored when implementing interfaces.

Interfaces require the method set to match; pointer receiver methods need pointer types to satisfy interfaces.

Why might you avoid using value receivers for large structs?

A Because value receivers can modify the original struct.

B Because value receivers cannot be used with methods.

C Because value receivers are slower to write.

D Because value receivers copy the entire struct, which is inefficient.

Value receivers copy the whole struct, which can be slow and use more memory for large structs.

Explain what a pointer receiver is and why it is useful in Go methods.

Think about how methods can change the data inside a struct.

Describe how Go handles calling pointer receiver methods on values and how this affects your code.

Consider what happens behind the scenes when you call a method.