검색결과 리스트

JAVA에 해당되는 글 19건

글

(12) 메소드 & 객체

JAVA/JAVA 이론 2018. 11. 1. 21:43
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
package hello;
 
//1. 속성변수 또는 메소드의 사용범위(scope)
//-> public , default(키워드 생략) , private ( getter / setter )
//2. 생성자(메소드) : 클래스 이름과 같음 객체가 생성될때 실행
//-> 기본생성자는 생략되는 경우가 대부분  리턴형식 없음
 
public class Hello
{
    //속성변수 ( 전역변수 - 초기값 0 , 객체 null,boolean은 false)
    
    public int n1;        // 모든 클래스에서 사용(접근)
    int n2;                // 같은 패키지 클래스에서만
    private int n3;        // 현재 클래스에서만
    
    public Hello()        // 기본 생성자
    {
        System.out.println("Hello 클래스 객첵가 생성됨");
    }
    
    // 속성 변수 초기화 하는 생성자
    public Hello(int n1, int n2, int n3)
    {
        this();        // 기본생성자 메소드 실행
        this.n1    = n1;
        this.n2 = n2;
        this.n3 = n3;
    }
    
    public void test1()
    {
        System.out.println("test1 : " + n1);
    }
    void test2()
    {
        System.out.println("test2 : " + n2);
    }
    private void test3()
    {
        int abc;    // 지역변수 , 초기값 설정안하면 오류
        // System.out.pritnln(abc);        // 오류
        System.out.println("test3 : " + n3);
    }
}
 
cs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
package hello;
 
 
public class HelloTest 
{
 
    public static void main(String[] args) 
    {
        Hello c1 = new Hello();
        //Hello()  -> 생성자 메소드
        
        c1.n1 = 10;
        c1.test1();
        c1.test2();
        //c1.test3();    // 오류 , private 접근권한 (scope)
    }


 
}
 
cs






1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
package hello;
 
public class Hello
{
    // 속성 접근 못함
    private String name;
    private int age;
    private double point;
    
    // 생성자 메소드 - 3개 속성 초기화
    // 새로운 형식의 생성자를 정의하면 기본 생성자는 필요시 생략 못하고 정의를 해야함
    public Hello(String name, int age , double point)
    {
        this.name = name;
        this.age = age;
        this.point = point;
    }
    
    public Hello()
    {
        
    }
    
    //getter , setter 메소드
    public String getName()
    {
        return name;
    }
    public void setName(String name)
    {
        this.name = name;
        // 인자로 받은 name을 속성 name에게 전달
        // this는 현재 자신의 객체
    }
    public int getAge()
    {
        return age;
    }
    public void setAge(int age)
    {
        this.age = age;
    }
    public double getPoint()
    {
        return point;
    }
    public void setPoint(double point)
    {
        this.point = point;
    }
    
    public String print()
    {
        return name + "(" + age + ")" + point + "포인트";
    }
    
}
 
cs



1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
package hello;
 
import java.util.Scanner;
 
public class HelloTest 
{
 
    public static void main(String[] args) 
    {
        Hello[] mem = new Hello[3];
        
        Scanner sc = new Scanner(System.in);
        int i =0;
        System.out.println("[[회원 관리 - 입력 ]]");
        
        while(i<3)
        {
            System.out.print("이름 >>> ");
            String name = sc.nextLine();
            
            System.out.print("나이 >>> ");
            int age = sc.nextInt();
            
            System.out.print("포인트 >>> ");
            double point = sc.nextDouble();
            
            // 객체 생성(초기화)하고 배열 인덱스 지정해서 참조
            mem[i] = new Hello(name,age,point);
            i++;
            sc.nextLine();


        }
        
        System.out.println("회원 입력 완료");
        System.out.println("\n[[회원 리스트]]");
        for(i=0;i<mem.length;i++)
        {
            System.out.println(mem[i].print());
        }
    }



        
    
 
}
 
cs


저작자표시 비영리 변경금지

'JAVA > JAVA 이론' 카테고리의 다른 글

(13) 문제  (0) 2018.11.01
(11) Method & Class  (0) 2018.10.30
(10) 2중 for 문 & 2차원 배열  (0) 2018.10.29
(9) String Method  (0) 2018.10.28
(8) Array  (0) 2018.10.25

설정

트랙백

댓글

1 2 3 4 5 ··· 19
지역로그 : 태그 : 방명록 : 관리자 : 글쓰기
태영_'s Blog is powered by Daum & Tattertools / Designed by Tistory

티스토리툴바