当值与类型为偶数时，TypeScript中的一些语法糖？

interface Person {
  name: string;
  age?: number;
}

const person: Person = {
  name: "John"
};

function greet(name: string, greeting: string = "Hello") {
  console.log(`${greeting}, ${name}!`);
}

greet("John"); // Output: Hello, John!
greet("Jane", "Hi"); // Output: Hi, Jane!

const person = {
  name: "John",
  age: 30
};

const { name, age } = person;
console.log(name); // Output: John
console.log(age); // Output: 30

const numbers = [1, 2, 3, 4, 5];
const [first, second, ...rest] = numbers;
console.log(first); // Output: 1
console.log(second); // Output: 2
console.log(rest); // Output: [3, 4, 5]

const value: any = "Hello";
const length: number = (value as string).length;
console.log(length); // Output: 5