Math 클래스 실습 public class MathEx01 { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub // 내림 System.out.println(Math.floor(3.2)); System.out.println(Math.floor(3.5)); System.out.println(Math.floor(3.7)); // 올림 System.out.println(Math.ceil(3.2)); System.out.println(Math.ceil(3.5)); System.out.println(Math.ceil(3.7)); // 반올림 System.out.println(Math.round(3.2)); Sy.. 더보기 주민등록 유효성 체크 import java.lang.*; public class JuminEx { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub String jumin = new String("주민등록번호"); String jumin1 = jumin.replace("-", ""); // - 삭제하기// System.out.println(jumin1); String[ ] datas = jumin1.split(""); // 숫자 쪼개기 for (String data : datas){// System.out.println(data); } //str -> int 강제 형변환 int id1 = Integer... 더보기 enum 실습 import java.util.HashMap; public classEnumsEx { /** * @param args */ public enumSeason {WINTER, SPRING, SUMMER, FALL} public static voidmain(String[] args) { // TODOAuto-generated method stub HashMap map = new HashMap(); map.put(Season.WINTER, "겨울"); map.put(Season.SPRING, "봄"); map.put(Season.SUMMER, "여름"); map.put(Season.FALL, "가을"); System.out.println(map.get(Season.WINTER)); System.out.print.. 더보기 Properties 실습 import java.util.Enumeration;import java.util.Properties; public class PropertiesEx { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Properties props = System.getProperties(); Enumeration enu = props.propertyNames(); while( enu.hasMoreElements()){ String key = (String)enu.nextElement(); String value = props.getProperty(key); System.out.println(ke.. 더보기 Hashtable 실습 import java.util.Collection;import java.util.Enumeration;import java.util.Hashtable;import java.util.Set; public class HashTableEx { /** * @param args */ public static void main(String[] args) { // TODO Auto-generated method stub Hashtable map = new Hashtable(); map.put("key1", "홍길동"); map.put("key2", "박문수"); map.put("key3", "이몽룡"); System.out.println(map.get("key1")); System.out.println(map.get.. 더보기 이전 1 ··· 23 24 25 26 27 28 29 ··· 37 다음