Swpark: Created page with "== 1.1 Java 입문 == ==== 프로그램 1.1 Java 프로그램==== package ds.ch01; public class JavaOne { static int count = 1; public static void main(String[] args) { System.out.println("The count is " + count); } } ==== 프로그램 1.2 메소드 정의와 호출의 예 ==== package ds.ch01; public class MinTest { public static void main(String[] args) {..."

2022-07-05T11:10:57Z

Created page with "== 1.1 Java 입문 == ==== 프로그램 1.1 Java 프로그램==== <syntaxhighlight lang="java"> package ds.ch01; public class JavaOne { static int count = 1; public static void main(String[] args) { System.out.println("The count is " + count); } } </syntaxhighlight> ==== 프로그램 1.2 메소드 정의와 호출의 예 ==== <syntaxhighlight lang="java"> package ds.ch01; public class MinTest { public static void main(String[] args) {..."

New page

== 1.1 Java 입문 ==

==== 프로그램 1.1 Java 프로그램====
<syntaxhighlight lang="java">
package ds.ch01;

public class JavaOne {
static int count = 1;

public static void main(String[] args) {
System.out.println("The count is " + count);
}
}
</syntaxhighlight>

==== 프로그램 1.2 메소드 정의와 호출의 예 ====
<syntaxhighlight lang="java">
package ds.ch01;

public class MinTest {
public static void main(String[] args) {
int a = 3;
int b = 7;
System.out.println(min(a, b));
}

public static int min(int x, int y) {
return x < y ? x : y;
}
}
</syntaxhighlight>

===1.1.2.4 매개변수 전달 ===
<syntaxhighlight lang="java">
package ds.ch01;

public class Test {
public int value;

static void callByValueTest() {
int i = 99;
System.out.println("before : i = " + i);
changeValue(i);
System.out.println(" after : i = " + i);
}

static void changeValue(int j) {
j = 88;
}

static void callByReferenceTest() {
Test t = new Test();
t.value = 99;
System.out.println("before : i = " + t.value);
changeValue(t);
System.out.println(" after : i = " + t.value);
}

static void changeValue(Test j) {
j.value = 88;
}

public static void main(String[] args) {
callByValueTest();
callByReferenceTest();
}
}
</syntaxhighlight>

실행결과

<syntaxhighlight lang="text">
before : i = 99
after : i = 99
before : i = 99
after : i = 88
</syntaxhighlight>

==== 프로그램 1.3 생성자와 equals(), toString()을 포함하고 있는 Date 클래스 ====
<syntaxhighlight lang="java">
package ds.ch01;

public class Date {
private int month;
private int day;
private int year;

public Date() {
month = 1;
day = 1;
year = 2022;
}

public Date(int month, int day, int year) {
this.month = month;
this.day = day;
this.year = year;
}

@Override
public boolean equals(Object obj) {
if (obj == null || !(obj instanceof Date))
return false;
Date d = (Date)obj;
return d.month == month && d.day == day && d.year == year;
}

@Override
public String toString() {
return month + "/" + day + "/" + year;
}

public static void main(String[] args) {
Date date1 = new Date();
Date date2 = new Date(1, 1, 2022);

System.out.println(date1);
System.out.println(date1);
System.out.println(date1 == date2);
System.out.println(date1.equals(date2));
}
}
</syntaxhighlight>

실행결과

<syntaxhighlight lang="text">
1/1/2022
1/1/2022
false
true
</syntaxhighlight>

자료구조/예제/1장 추상 데이터 타입과 객체지향 방법 - Revision history