集合.LinkedList

LinkedList

链表结构实现，增删快，查询慢

package jihe;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.ListIterator;

/**
 * LinkedList的使用
 * 存储结构：双向链表
 */
public class Demo07 {
    public static void main(String[] args) {
        //创建集合
        LinkedList linkedList = new LinkedList();
        //1.添加元素
        Student s1 = new Student("小A",20);
        Student s2 = new Student("小B",22);
        Student s3 = new Student("小C",24);
        linkedList.add(s1);
        linkedList.add(s2);
        linkedList.add(s3);
        System.out.println("元素个数:"+linkedList.size());
        System.out.println(linkedList.toString());
        //2.删除
        //linkedList.remove(0);
        //System.out.println("删除之后："+linkedList.size());

        //3.遍历
        //3.1for遍历
        System.out.println("--------3.1for--------");
        for (int i = 0; i < linkedList.size(); i++) {
            System.out.println(linkedList.get(i));
        }
        //3.2增强for
        System.out.println("--------3.2增强for--------");
        for (Object object : linkedList) {
            System.out.println(object);
        }
        //3.3使用迭代器
        System.out.println("--------3.3使用迭代器--------");
        Iterator it = linkedList.iterator();
        while (it.hasNext()){
            Student s = (Student)it.next();
            System.out.println(s.toString());
        }
        //3.4使用列表迭代器
        System.out.println("--------3.4使用列表迭代器--------");
        ListIterator lit = linkedList.listIterator();
        while (lit.hasNext()){
            Student s = (Student)lit.next();
            System.out.println(s.toString());
        }
        //4.判断
        System.out.println(linkedList.contains(s1));
        System.out.println(linkedList.isEmpty());
        //5.获取
        System.out.println(linkedList.indexOf(s2));
    }
}

package jihe;

import java.util.Objects;

public class Student {
    private String name;
    private int age;

    public Student() {
    }
    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }
    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;
    }
    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';

    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Student student = (Student) o;
        return age == student.age && Objects.equals(name, student.name);
    }

    @Override
    public int hashCode() {
        return Objects.hash(name, age);
    }
}

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