Classes

class Foo {
  #item
 
  constructor(value) {
    this.#item = value
  }
 
  static create(value) {
    return new Foo(value)
  }
 
  getItem() {
    return this.#item
  }
 
  setItem(value) {
    this.#item = value
  }
}
 
const foo = Foo.create('bar')
console.log(foo.getItem()) // bar
 
foo.setItem('qux')
console.log(foo.getItem()) // qux

package main
 
import "fmt"
 
// Base holds a value and the methods to get/set it. The lowercase
// (unexported) field is private to the package, not to the type.
type Base struct {
	item string
}
 
func (b *Base) GetItem() string {
	return b.item
}
 
func (b *Base) SetItem(value string) {
	b.item = value
}
 
// Foo embeds Base, so it gets GetItem and SetItem for free —
// Go's alternative to class inheritance.
type Foo struct {
	Base
}
 
func NewFoo(value string) *Foo {
	return &Foo{Base: Base{item: value}}
}
 
func main() {
	foo := NewFoo("bar")
	fmt.Println(foo.GetItem()) // bar
 
	foo.SetItem("qux")
	fmt.Println(foo.GetItem()) // qux
}

struct Foo {
    item: String, // no `pub`: private to the module, like Go
}
 
impl Foo {
    fn create(value: &str) -> Self {
        Foo { item: value.to_string() }
    }
 
    fn get_item(&self) -> &str {
        &self.item
    }
 
    fn set_item(&mut self, value: &str) {
        self.item = value.to_string();
    }
}
 
fn main() {
    let mut foo = Foo::create("bar");
    println!("{}", foo.get_item()); // bar
 
    foo.set_item("qux");
    println!("{}", foo.get_item()); // qux
}

class Foo {
    private var item: String
 
    init(_ value: String) {
        item = value
    }
 
    static func create(_ value: String) -> Foo {
        Foo(value)
    }
 
    func getItem() -> String {
        item
    }
 
    func setItem(_ value: String) {
        item = value
    }
}
 
let foo = Foo.create("bar") // `let` only fixes the reference; classes are reference types
print(foo.getItem()) // bar
 
foo.setItem("qux") // the object's contents can still change even though `foo` is `let`
print(foo.getItem()) // qux

static class Foo {
    private String item;
 
    private Foo(String value) {
        item = value;
    }
 
    static Foo create(String value) {
        return new Foo(value);
    }
 
    String getItem() {
        return item;
    }
 
    void setItem(String value) {
        item = value;
    }
}
 
void main() {
    Foo foo = Foo.create("bar");
    IO.println(foo.getItem()); // bar
 
    foo.setItem("qux");
    IO.println(foo.getItem()); // qux
}