V does not have classes. But one can define methods for types. A method is a function that has a special receiver argument, only a receiver of the specified type can execute this function. The receiver has its own argument list between fn and the method name.
struct User {
name string
email string
age int
fn (u User) can_register() bool {
return u.age > 15
fn (u mut User) has_birthday() {
u.age += 1
fn main() {
mut bob := User {
name: 'Bob'
email: '[email protected].com'
age: 15
alice := User {
name: 'Alice'
email: '[email protected]'
age: 17
println(bob.can_register()) // false
println('Bob needs to be 16 to register, but he only is ${bob.age}.') // Bob needs to be 16 to register, but he only is 15.
println(alice.can_register()) // true
println(bob.age) // 16
This code above realizes two methods for receivers u of type User. Note that the method has_birthday() has a mut receiver, this is needed here since we want to change its data. The convention of V is not to use receiver names like self, this or similar things but a short, preferably one letter long, name.


  1. 1.
    Create a method for the type Person that determines whether a person is underage or not.
  2. 2.
    Create a method that determines whether an Animal has fur or not.
Last modified 3yr ago