2021-08-11(Constructor)

생성자

• this()
  • 자기 자신 클래스의 다른 생성자를 호출하기 위해 사용되는 생성자
  • 코드의 간결성(중복코드 제거를 위해 사용)

House.java

package kr.ac.daegu.bsy;

class House {
    int price;
    String dong;
    int size;
    String kind;

    public House(){
        //System.out.println(this보다 앞에서 실행");
        this(100,32,"상계동","아파트");
    }
    public House(int price){
        this(price,32,"상계동","아파트");
    }
    public House(int price,int size){
        this(price,size,"상계동","아파트");
    }
    public House(int price,int size,String dong){
        this(price,size,dong,"아파트");
    }

    public House(int price, int size, String dong, String kind) {
        this.price = price;
        this.size = size;
        this.dong = dong;
        this.kind = kind;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public String getDong() {
        return dong;
    }

    public void setDong(String dong) {
        this.dong = dong;
    }

    public int getSize() {
        return size;
    }

    public void setSize(int size) {
        this.size = size;
    }

    public String getKind() {
        return kind;
    }

    public void setKind(String kind) {
        this.kind = kind;
    }

    @Override
    public String toString() {
        return "House " +
                "price=" + price +
                ", dong='" + dong + '\'' +
                ", size=" + size +
                ", kind='" + kind + '\''
                ;
    }
}

ThisConstructorTest.java

package kr.ac.daegu.bsy;

public class ThisConstructorTest {

    public static void main(String[] args) {
        System.out.println("ConstructorPractice2");
        //p.201 ~ p.202
        House house1 = new House();
        System.out.println(
                "house.price = " + house1.price
                + ", house.size = " + house1.size
                + ", house.dong = " + house1.dong
                + ", house.kind = " + house1.kind);

        House house2 = new House(300);
            System.out.println(
                "house.price = " + house2.price
                + ", house.size = " + house2.size
                + ", house.dong = " + house2.dong
                + ", house.kind = " + house2.kind);

        House house3 = new House(300,40);
        System.out.println(
                "house.price = " + house3.price
                        + ", house.size = " + house3.size
                        + ", house.dong = " + house3.dong
                        + ", house.kind = " + house3.kind);

        House house4 = new House(300,40,"서초동");
        System.out.println(
                "house.price = " + house4.price
                        + ", house.size = " + house4.size
                        + ", house.dong = " + house4.dong
                        + ", house.kind = " + house4.kind);

        House house5 = new House(300,40,"서초동","빌라");
        System.out.println(
                "house.price = " + house5.price
                        + ", house.size = " + house5.size
                        + ", house.dong = " + house5.dong
                        + ", house.kind = " + house5.kind);

}


}

ThisConstructor2.java (ThisConstructor.java 메소드화)

package kr.ac.daegu.bsy;

public class ThisConstructorTest2 {
    public static void main(String[] args){
        System.out.println("ConstructorPractice2");
        //p.201 ~ p.202
        House house1 = new House();
        printHouse(house1); // house의 멤버변수들 값을 출력하는 메소드

        House house2 = new House(300);
        printHouse(house1);

        House house3 = new House(300, 40);
        printHouse(house1);

        House house4 = new House(300,40,"서초동");
        printHouse(house1);

        House house5 = new House(300,40,"서초동","빌라");
        printHouse(house1);
    }

    private static void printHouse(House house) {
        System.out.println(house.toString());
    }
}