Dynamic Type

The dynamic keyword declares a variable with a runtime-determined type. Dynamic variables can hold any value and their type can change during execution.

---

Declaring Dynamic Variables

// Explicit dynamic
x is 0 as dynamic;
y as dynamic;

// Bare declaration — implicitly dynamic
a;                  // dynamic, uninitialized

A bare declaration (just an identifier followed by a semicolon) automatically becomes a dynamic variable.

---

Dynamic Behavior

Dynamic variables accept any value type:

value as dynamic;
value is 42;         // holds an int
value is "hello";    // now holds a string
value is true;       // now holds a bool

---

Real Example

From IsOptionalDynamic.mx:

RunFmaBench method() as int {
    a;                  // dynamic, bare declaration
    b 10;               // int shorthand
    c as dynamic;       // explicit dynamic
    d is 0 as dynamic;  // dynamic with initial value

    Print("is-optional + dynamic demo");
    return 0;
}

---

When to Use dynamic

Use Case	Recommendation
Type is known at compile time	Use a concrete type (int, string)
Type varies at runtime	Use dynamic
Interfacing with untyped data	Use dynamic
Prototyping	Use dynamic, refine later

---

Next Steps

• Type Casting — Converting between types with as, maybe, and then