> There, the reference to `i` is being mutated.
That's rebinding. Mutation is when you change the state of an object. Variables are not objects. You can't have a reference (aka pointer) pointing to a variable.
That's rebinding. Mutation is when you change the state of an object. Variables are not objects. You can't have a reference (aka pointer) pointing to a variable.
tombert's point (I think) is that in a functional setting, factorial(n) is always factorial(n). In an imperative setting, first it's 1, then 2, then 6, then 24, etc.
Here's factorial calculated imperatively in C#.
public async Task Factorial() {
long primitiveResult = 1L;
Wrapped<long> objectResult = new Wrapped<long>(1L);
var observer = new Task(ObserveVariable);
observer.Start();
for (var i = 2; i <= 15; i++) {
primitiveResult *= i;
objectResult = new Wrapped<long>(objectResult.Value * i);
await Task.Delay(100);
}
observer.Wait();
return;
void ObserveVariable() {
while (primitiveResult != 1307674368000 || objectResult.Value != 1307674368000) {
Thread.Sleep(100);
}
}
}
If I were to write
var i = new Obj(2)
// do stuff 1
i = new Obj(3)
// do stuff 2
What?
int a;
int * p = &a;
?