54: JavaScript prototype

1. with 와 in 문법에 대하여 설명하시오.

//code
      function print(p) {
        document.write(p);
      }
      function println(p) {
        print(p);
        print("<br>");
      }
      let object = {};
      object.property1 = 1;
      object.property2 = 2;
      object.property3 = 3;
      with (object) {
        println(property1);
        println(property2);
        println(property3);
      }
      for (let x in object) {
        println(object[x]);
      }

2.아래를 프로그래밍 하시오.

var circle = new Circle();
circle.setRaius(10);
circle.getArea(); 			//원넓이 출력
//
var rec = new Rectangle();
rec.setWidth(10);
rec.setHeight(10);
rec.getArea(); 				//원넓이 출력

//code
      function print(p) {
        document.write(p);
      }
      function println(p) {
        print(p);
        print("<br>");
      }
      function Circle() {}
      Circle.prototype.radius = 0;
      Circle.prototype.setRadius = function (radius) {
        this.radius = radius;
      };
      Circle.prototype.getArea = function () {
        println(Math.PI * Math.pow(this.radius, 2));
      };
      function Rectangle() {}
      Rectangle.prototype.width = 0;
      Rectangle.prototype.height = 0;
      Rectangle.prototype.setWidth = function (width) {
        this.width = width;
      };
      Rectangle.prototype.setHeight = function (height) {
        this.height = height;
      };
      Rectangle.prototype.getArea = function () {
        println(this.width * this.height);
      };

3. prototype 에 대하여 설명하시오.

//code
      function print(p) {
        document.write(p);
      }
      function println(p) {
        print(p);
        print("<br>");
      }
      function Constructor() {}
      Constructor.prototype.property = 1;
      Constructor.prototype.setProperty = function (property) {
        this.property = property;
      };
      Constructor.prototype.getProperty = function () {
        return this.property;
      };
      let c = new Constructor();
      println(c.getProperty());
      c.setProperty(3);
      println(c.property);

4. 아래 코드 실행시 처음과 끝에 실행되는 구문에 대하여 설명하시오?

function User(name) {
  this.name = name;
  this.isAdmin = false;
}								//Object Constructor
//
let user = new User("보라");		//Calling the constructor as instance

5. 생성자 함수에 대하여 설명하시오.

//code
      function print(p) {
        document.write(p);
      }
      function println(p) {
        print(p);
        print("<br>");
      }
      function Constructor(p1, p2, p3) {
        this.p1 = p1;
        this.p2 = p2;
        this.p3 = p3;
      }
      let c = new Constructor(1, 2, 3);
      with (c) {
        println(p1);
        println(p2);
        println(p3);
      }