list

• 增加 .add()
• 刪除 .remove()
• 遍歷 for或者iterator
  .next()
  .previous()
• 判斷 .contains()
  .isEmpty()
• 獲取下標 .indexOf()

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;


public class Demo01 {
    public static void main(String[] args) {
        //建立集合
        List tree = new ArrayList();
        //1.新增集合元素
        tree.add("蘋果");
        tree.add("榴蓮");
        tree.add("香蕉");
        System.out.println(tree);
        System.out.println("總數：" + tree.size());

        //2.移除集合元素
        /*  tree.remove("蘋果");
        System.out.println("總數："+tree.size());
        tree.clear();
        System.out.println("總數："+tree.size());
        */

        //3.遍歷集合
        System.out.println("--------------增強for迴圈------------------");
        for (Object o : tree) {
            System.out.println(o);
        }
        System.out.println("--------------iterator迭代器迴圈------------------");
        Iterator A = tree.iterator();
        while (A.hasNext()) {
            String next = (String) A.next();
            System.out.println(next);
            //tree.remove  不允許使用原物件刪除
        }
        System.out.println("--------------ListIterator迭代器迴圈------------------");
        //和iterator迭代器的區別，ListIterator可以向前或向後操作
        ListIterator B = tree.listIterator();
        while (B.hasNext()) {
            System.out.println(B.nextIndex()+":"+ B.next());
        }
        while (B.hasPrevious()){
            System.out.println(B.previousIndex()+":"+ B.previous());
        }

        System.out.println("--------------判斷------------------");
        //4.判斷
        System.out.println(tree.contains("蘋果"));
        System.out.println(tree.isEmpty());
        //獲取位置
        System.out.println(tree.indexOf("蘋果"));

    }
}