与扩展语法相关的奇怪语法

const name = 'John';
const age = 25;

const person = {
  name,
  age,
  sayHello() {
    console.log(`Hello, my name is ${this.name}.`);
  },
  [`${name}_age`]: age
};

const numbers = [1, 2, 3, 4, 5];

const [first, second, ...rest] = numbers;

console.log(first); // 1
console.log(second); // 2
console.log(rest); // [3, 4, 5]

function greet(name = 'Guest', { age, city }) {
  console.log(`Hello, ${name}! You are ${age} years old and live in ${city}.`);
}

const person = {
  age: 25,
  city: 'New York'
};

greet('John', person);

const name = 'John';
const age = 25;

const message = `Hello, my name is ${name} and I am ${age} years old.`;

console.log(message); // Hello, my name is John and I am 25 years old.