Ex12_3 코드

package org.javaro.lecture; import java.util.*; public class Ex12_3 { public static void main(String[] args) { System.out.println("조병수-20191121-콜렉션과 제너릭"); ArrayList<String> arrayList = new ArrayList<String>(); int idx = 0; String obj1 = "Korea"; String obj2 = "Seoul"; String obj3 = "Daejeon"; arrayList.add(obj1); System.out.println("1="+arrayList.get(0)); arrayList.add(idx,obj2); for(int i = 0; i <arrayList.size(); i++) {System.out.println("2="+arrayList.get(i));} arrayList.set(idx,obj3); for(int i = 0; i <arrayList.size(); i++) {System.out.println("3="+arrayList.get(i));} idx = arrayList.indexOf(obj1); arrayList.remove(idx); int count = arrayList.size(); System.out.println(count); Object[] str = arrayList.toArray(); for(int i = 0; i <str.length; i++) {System.out.println((String)str[i]);} arrayList.clear(); } }

실행창

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