Observer

Évènements (C#)

public class Truc
{
    public event Action<int> ContentUpdated;

    public void DoThing()
    {
        ContentUpdated?.Invoke(123);
    }
}

var obj = new Truc();
obj.ContentUpdated += val => Console.WriteLine(val);

Event listeners (JS, PHP, ...)

document.getElementById("myButton").addEventListener("click", function() {
    alert("Clicked!");
});

Strategy

Pointeurs de fonctions (C, C++) / fonctions déléguées (C#) / fonctions de première classe (JS, PHP) / fonctions lambda (Java)

int Carre(int x) => x * x;
int Double(int x) => x + x;
Func<int, int> operation = Carre;
int result = operation(123);

function carre(x) { return x * x; }
function double(x) { return x + x; }
const operation = carre;
const result = operation(123);

Iterator

foreach (C#, PHP) / for..of (JS) / for..: (Java) / for (Python)

var squares = new [] { 1, 4, 8, 2 }.Select(y => Carre(y));
foreach (var x in squares) { ... }

squares = (carre(y) for y in [1, 4, 8, 2])
for x in squares: ...

Bridge

Interfaces (C#, Java, C++)

public interface ITruc { int Fonction(); }
public class Concrete1 : ITruc { public int Fonction() => 5; }
public class Concrete2 : ITruc { public int Fonction() => 123; }
ITruc implementation = new Concrete1();

Visitor (double dispatch)

Pattern matching (C#, Scala)

public int Visit(Node node) => node switch 
{
    IntNode(var value) => value,
    AddNode(var x, var y) => Visit(x) + Visit(y),
    MulNode(var x, var y) => Visit(x) * Visit(y)
}

Builder

Valeurs par défaut de paramètres (C#, Python, C++, JS, VB)

public class Car
{
    public Car(int wheels = 4, int doors = 5, TransmissionType transmission = Traction, ...)
    {
        ...
    }
}