Golang pointers and syntax differences

May 7, 2022

I am doing a course on Golang and I can´t tell if there is an underlying difference in these two code options, or if it is just a matter of different admitted syntax. In this last case, what option is considered a better practice?

I am getting the same values when printing.

I hope it is possible to understand the question. I tried to be the most concise possible and ommit code that could be unnecesary like the imports of packages and the definition of the type person, so I am just showing the instance of it.

Thank you all!

// ==============================================================================================
// OPTION 1
// ==============================================================================================

func main() {
    person_1 := person{
        firstName: "Jack",
        lastName:  "Daniels",
        contactInfo: contactInfo{
            email:   "jack.daniels@email.com",
            zipCode: 1234,
        },
    }

    // To first make a pointer of the person and then pass that pointer to the updateName function
    person_1_pointer := &person_1
    person_1_pointer.updateName("John")
    

}

//Receiver takes a pointer to a type person and then converts that pointer to a value and access
//the firstName attribute to change it.
func (p *person) updateName(newFirstName string) {
    (*p).firstName = newFirstName
}


// ==============================================================================================
// OPTION 2
// ==============================================================================================
    
    // Without defining a pointer first and calling the updateName on the person instance itself.
    person_1.updateName("John")
    

//Receiver takes a pointer to a type person and then converts that pointer to a value and access
//the firstName attribute to change it.
func (p *person) updateName(newFirstName string) {
    p.firstName = newFirstName
}