Day 43-2. [JavaScript] 프로퍼티

// function Circle(radius) {
//     this.radius = radius
//     this.getArea = function(){
//         return Math.PI * this.radius ** 2;
//     }
// }
function Circle(radius) {
    this.radius = radius
}
Circle.prototype.getArea = function(){
    return Math.PI * this.radius ** 2;
}

Circle.prototype.PI = Math.PI // circle1.pi로만 접근 가능
Circle.PI = Math.PI // circle.pi로만 접근 가능(생성자이름)

const circle1 = new Circle(1);
const circle2 = new Circle(2);

console.log(circle1.getArea == circle2.getArea)
console.log(circle1.getArea === circle2.getArea)

console.log(circle1.getArea())
console.log(circle2.getArea())

console.log(circle1.PI)
console.log(circle1.__proto__.PI) // 이거랑
console.log(Circle.PI) // 이거랑 동일

console.log("--------------------")

// Date
// Date 타입의 인스턴스에 toMyString이라는 메서드를 제작 >
// yyyy-MM-DD HH:MM:SS 형태의 시간정보를 반환

Number.prototype.lz = function(){
    return this < 10 ? "0" + this : ""+this;
}
Date.prototype.toMyString = function(){
    return `${this.getFullYear()}/${(this.getMonth() + 1).lz()}/${this.getDate().lz()}`
    + `  ${this.getHours().lz()}:${this.getMinutes().lz()}:${this.getSeconds().lz()}`
}

const now = new Date();
console.log(now.toMyString())

const Person = (function(){
    function Person(name){
        this.name = name
    }

    Person.prototype.sayHello = function(){
        console.log(`Hi! My name is ${this.name}`)
    }
    return Person
}())

const me = new Person('Lee')

me.sayHello()

me.sayHello = function(){
    console.log(`Hi! My name is ${this.name}`)
}

me.sayHello()

// 프로퍼티 제거
delete me.sayHello;
me.sayHello;

me.sayHello()

delete Person.prototype.sayHello;

// me.sayHello();