Part08 - this

Book

package com.mywork.ex;

public class Book {
	/*
	  this

	  1. 생성된 객체(인스턴스) 자신의 주소(참조, 레퍼런스)
	  2. 생성된 객체(인스턴스)가 자신을 부르는 방식
	  3. 클래스 구성 요소에 this 활용
	    1) 필드 : this.필드
	    2) 생성자 : this()
	*/
	// Field
	String title;
	String writer;
	int price;
	int salesVolume;
	boolean isBestSeller;
	
	// Constructor
	Book(String title, int price){
		this(title, "작자미상", price);
	}
	Book(String title, String writer, int price){
		this.title = title;
		this.writer = writer;
		this.price = price;
	}
	/*
	Book(String title, int price) {
		this.title = title;
		this.writer = "작자미상";
		this.price = price;
	}
	Book(String title, String writer, int price) {
		this(title, price);  // 매개변수 2개인 생성자를 호출하는 부분!
		                     // 반드시 먼저 호출해야 한다. 나중에 호출할 수 없다.
		this.writer = writer;
	}
	*/
	
	// Method
	void setSalesVolume(int salesVolume) {
		this.salesVolume = salesVolume;
		if (salesVolume >= 1000) {
			isBestSeller = true;
		} else {
			isBestSeller = false;
		}
	}
	void output() {
		System.out.println("책 제목 : " + title);
		System.out.println("책 저자 : " + writer);
		System.out.println("책 가격 : " + price);
		System.out.println("책 판매량 : " + salesVolume);
		System.out.println("베스트셀러 유무 : " + (isBestSeller ? "베스트셀러" : "일반서적"));
	}
	
}

BookMain

package com.mywork.ex;

public class BookMain {
	public static void main(String[] args) {

		Book book1 = new Book("콩쥐팥쥐", 10000);
		Book book2 = new Book("자바의 정석", "남궁성", 35000);
		
		book1.setSalesVolume(500);
		book2.setSalesVolume(1500);
		
		book1.output();
		book2.output();
		
	} 
}

Local

package com.mywork.ex;

public class Local {
	
	// Field
	String name;
	int age;
	String sn;
	boolean isKorean;
	
	// Constructor
	Local(String name, int age) {
		this(name, age, null);
	}
	Local(String name, int age, String sn) {
		this.name = name;
		this.age = age;
		this.sn = sn;
		if(sn != null) {
			this.isKorean = sn.charAt(7) <= '4' ? true : false;
		}
	}
	// Method
	void output() {
		System.out.println("이름 : " + name);
		System.out.println("나이 : " + age);
		System.out.println("주민등록번호 : " + (sn == null ? "없음" : sn));
		System.out.println(isKorean ? "한국인" : "외국인");
	}
}

LocalMain

package com.mywork.ex;

public class LocalMain {
	public static void main(String[] args) {

		Local person1 = new Local("홍길동", 20, "901215-1234567");
		Local person2 = new Local("응우엔티엔", 21, "911215-6789123");
		Local person3 = new Local("james", 22);
		
		person1.output();	System.out.println("-----");
		person2.output();	System.out.println("-----");
		person3.output();
	}
}

Rect

package com.mywork.ex;

public class Rect {

	// Field
	int width;   // this.width
	int height;  // this.height
	
	// Constructor
	Rect(int width, int height) {
		this.width = width;
		this.height = height;
	}
	
	// Method
	void setWidth(int width) {
		this.width = width;
	}
	void setHeight(int height) {
		this.height = height;
	}
	void output() {
		System.out.println("너비 : " + width);
		System.out.println("높이 : " + height);
	}
	
}

RectMain

package com.mywork.ex;

public class RectMain {

	public static void main(String[] args) {
		
		Rect nemo = new Rect(1, 2);
		nemo.output();
		
		nemo.setWidth(10);
		nemo.setHeight(20);
		nemo.output();
		
	}
	
}