List

ArrayList
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package edu.xcdq.list;

import java.util.ArrayList;

public class ArrayListDemo01 {
public static void main(String[] args) {
String [] str = new String[] { "1e21" , "12q" , "aqwdfqw"};
str[0] = "111";
str[1] = "222";
str[2] = "333";
// 删除位置为1的元素
str[0] = str[2];
str[2] = null;

    ArrayList list = new ArrayList<>();     //  数组列表  底层是数组
    list.add("111");
    list.add("222");
    list.add("333");
    list.add("444");
    list.add("555");        //  增加
    System.out.println(list);
    list.remove(1);     //  删除
    list.remove("444");
    System.out.println(list);
    list.set(2 ,"555555");      //  修改
    System.out.println(list);

    //  查询
    for (String l : list) {
        System.out.println(l + "\t");
    }

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

}

}
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LinkedList
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package edu.xcdq.list;

import java.util.ArrayList;
import java.util.LinkedList;

public class LinkedListDemo01 {
public static void main(String[] args) {
String[] str = new String[]{"1e21", "12q", "aqwdfqw"};
str[0] = "111";
str[1] = "222";
str[2] = "333";
// 删除位置为1的元素
str[0] = str[2];
str[2] = null;

    LinkedList list = new LinkedList<>();     //  数组列表  底层是数组
    list.add("111");
    list.add("222");
    list.add("333");
    list.add("444");
    list.add("555");        //  增加
    System.out.println(list);
    list.remove(1);     //  删除
    list.remove("444");
    System.out.println(list);
    list.set(2, "555555");      //  修改
    System.out.println(list);

    //  查询
    for (String l : list) {
        System.out.println(l + "\t");
    }

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


}

}
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