Declaring a Constant
Rust has two different types of constants which can be declared in any scope including global. Both require explicit type annotation:
const: An unchangeable value (the common case).
static: A possibly mutable variable with
'staticlifetime. The static lifetime is inferred and does not have to be specified. Accessing or modifying a mutable static variable is
// Globals are declared outside all other scopes. static LANGUAGE: &str = "Rust"; const THRESHOLD: i32 = 10;