• 기본 구조

class Person {
    // constructor (생성자)
    constructor(name, age) {
        // fields
        this.name = name;
        this.age = age;
    }

    // methods (메소드)
    speak() {
        console.log(`${this.name}: hello!`);
    }
}

const ellie = new Person('ellie', 20);
console.log(ellie.name); // ellie
console.log(ellie.age);  // 20
ellie.speak();           // ellie: hello!