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方法演示：

package exercise;

import java.util.ArrayList;
import java.util.List;

public class ListDemo1 {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        list.add("hello");
        list.add("world");
        list.add("java");
        System.out.println(list);

        list.add(1, "javaee");
        System.out.println(list);

        String remove = list.remove(2);
        System.out.println(remove + " " + list);

        String javaSe = list.set(1, "javaSe");
        System.out.println(javaSe + " " + list);

        for (int i = 0; i < list.size(); i++) {
            System.out.print(list.get(i) + " ");
        }
    }
}

tips:

package exercise;

import java.util.ArrayList;
import java.util.List;

public class ListDemo2 {
    public static void main(String[] args) {
        //List集合中的两个删除方法
        List<Integer> list = new ArrayList<>();
        list.add(1);
        list.add(2);
        list.add(3);
        //当方法出现重载时，优先调用形参和实参类型一致的那个方法。
        list.remove(1);
        System.out.println(list);
        //如不想这样，则需要手动装箱
        Integer i = Integer.valueOf(1);
        list.remove(i);
        System.out.println(list);
    }
}

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方法演示：

package exercise;

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

public class ListDemo3 {
    public static void main(String[] args) {
        List<String> list = new ArrayList<>();
        list.add("hello");
        list.add("world");
        list.add("java");

        Iterator<String> it = list.iterator();
        while (it.hasNext()) {
            String s = it.next();
            System.out.println(s);
        }
        System.out.println("=======");
        for (String s : list) {
            System.out.println(s);
        }
        System.out.println("=======");
        list.forEach(s -> System.out.println(s));
        System.out.println("=======");
        for (int i = 0; i < list.size(); i++) {
            System.out.println(list.get(i));
        }
        System.out.println("=======");
        //相比迭代器，额外添加了一个方法。在遍历过程中，可以添加元素
        ListIterator<String> s = list.listIterator();
        while (s.hasNext()) {
            String str = s.next();
            if ("world".equals(str)) {
                s.add("javaee");
            }
        }
        System.out.println(list);
    }
}

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