List的实现类

devtools/2024/10/18 19:29:22/

1.ArrayList（数组）

（1）代码

新建学生类：

java">package com.collection;public class Student {private String name;private int age;//添加构造方法 都是使用alt+enter快捷键public Student() {this.name = name;this.age = age;}//添加get set方法public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}//重写toString方法@Overridepublic String toString() {return "Student [name=" + name + ", age=" + age + "]";}
}

ArrayList的使用：

java">package com.collection;import java.util.ArrayList;
import java.util.Iterator;/*** ArrayList的使用* 存储结构是数组，查找遍历速度快，增删慢*/
public class Demo04 {public static void main(String[] args) {//创建集合ArrayList arrayList = new ArrayList<>();//创建对象Student s1 = new Student();s1.setName("John");s1.setAge(23);Student s2 = new Student();s2.setName("Jane");s2.setAge(22);Student s3 = new Student();s3.setName("Jack");s3.setAge(21);//1添加元素arrayList.add(s1);arrayList.add(s2);arrayList.add(s3);System.out.println("元素个数：" + arrayList);//2删除元素
//        arrayList.remove(s1);
//        arrayList.remove(1);System.out.println(arrayList);//3遍历元素System.out.println("-----迭代器--------");Iterator it = arrayList.iterator();while (it.hasNext()) {Student student = (Student) it.next();System.out.println(student);}//其他方法见之前的博客//4判断System.out.println(arrayList.isEmpty());//查找System.out.println(arrayList.indexOf(s2));}
}

结果：