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ArrayList集合的使用

时间:2018-05-15 19:33:27      阅读:144      评论:0      收藏:0      [点我收藏+]

标签:自定义数据类型   格式   引用   操作   print   switch   opp   csu   can   

import java.util.ArrayList;
class Demo02 
{
    public static void main(String[] args) 
    {
        method3();
    }
    public static void method1(){
        ArrayList<String> list = new ArrayList<String>();
        list.add("后裔");
        list.add("李元芳");
        list.add("猴子");
        System.out.println(list.get(0));
        System.out.println(list.size());
        for(int i = 0;i<list.size();i++){
             System.out.println(list.get(i));
        }
        
    }
    public static void method2(){
        ArrayList<phone> arr = new ArrayList<phone>();
        phone p1 = new phone();
        p1.brands = "oppo";
        p1.size = 5.5;
        p1.yanse = "red";
        arr.add(p1);
        phone p2 = new phone();
        p2.brands = "vivo";
        p2.size = 4.7;
        p2.yanse = "black";
        arr.add(p2);
        for(int i = 0;i<arr.size();i++){
               System.out.println(arr.get(i).brands+"\t"+arr.get(i).size+"\t"+arr.get(i).yanse);
        }
    }
    public static void method3(){
        ArrayList<Integer> arr = new ArrayList<Integer>();
        arr.add(100);
        arr.add(50);
        //指定位置插入数值
        arr.add(0,200);
        //删除指定位置数值
        arr.remove(1);
        //清空
        //arr.clear();
        //修改指定位置元素
        arr.set(0,30);
        for(int i = 0;i<arr.size();i++){
              System.out.println(arr.get(i));
        }
    }

}
public class Test01 
{
    public static void main(String[] args) 
    {
        Dianfanguo dfg = new Dianfanguo();
        Car c = new Car();
        Student s = new Student();
        dfg.brands = "格兰仕";
        dfg.size = 20;
        dfg.color = "红色";
        System.out.println("品牌:"+dfg.brands);
        System.out.println("尺寸:"+dfg.size);
        System.out.println("颜色:"+dfg.color+"\n");
        c.brands = "科尼塞克";
        c.size = "4.0L";
        c.leixing = "跑车";
        System.out.println("品牌:"+c.brands);
        System.out.println("排量:"+c.size);
        System.out.println("类型:"+c.leixing+"\n");
        s.name = "奥巴马";
        s.age = 50;
        s.sex = "";
        System.out.println("姓名:"+s.name);
        System.out.println("年龄:"+s.age);
        System.out.println("性别:"+s.sex+"\n");
    }
}

 

//ArrayList集合写随机点名
import java.util.ArrayList; import java.util.Random; import java.util.Scanner;
class zuoye { public static void main(String[] args) { //cunchu(); //bianli(); //suiji(); //cz(); //sj(); //yg(); } public static void cunchu(){ ArrayList<Stu> arr = new ArrayList<Stu>(); Stu s0 = new Stu(); s0.name = "董斌"; s0.age = 20; Stu s1 = new Stu(); s1.name = "张锐"; s1.age = 21; Stu s2 = new Stu(); s2.name = "王荣臣"; s2.age = 22; Stu s3 = new Stu(); s3.name = "韩凯"; s3.age = 23; Stu s4 = new Stu(); s4.name = "张禄"; s4.age = 24; Stu s5 = new Stu(); s5.name = "刘继勋"; s5.age = 25; Stu s6 = new Stu(); s6.name = "张维"; s6.age = 26; Stu s7 = new Stu(); s7.name = "牛攀"; s7.age = 28; Stu s8 = new Stu(); s8.name = "魏中豪"; s8.age = 29; arr.add(s0); arr.add(s1); arr.add(s2); arr.add(s3); arr.add(s4); arr.add(s5); arr.add(s6); arr.add(s7); arr.add(s8); } public static void bianli(ArrayList<Stu> arr){ ArrayList<Stu> arr = new ArrayList<Stu>(); Stu s0 = new Stu(); s0.name = "董斌"; s0.age = 20; Stu s1 = new Stu(); s1.name = "张锐"; s1.age = 21; Stu s2 = new Stu(); s2.name = "王荣臣"; s2.age = 22; Stu s3 = new Stu(); s3.name = "韩凯"; s3.age = 23; Stu s4 = new Stu(); s4.name = "张禄"; s4.age = 24; Stu s5 = new Stu(); s5.name = "刘继勋"; s5.age = 25; Stu s6 = new Stu(); s6.name = "张维"; s6.age = 26; Stu s7 = new Stu(); s7.name = "牛攀"; s7.age = 28; Stu s8 = new Stu(); s8.name = "魏中豪"; s8.age = 29; arr.add(s0); arr.add(s1); arr.add(s2); arr.add(s3); arr.add(s4); arr.add(s5); arr.add(s6); arr.add(s7); arr.add(s8); System.out.println("姓名\t年龄"); for(int i = 0;i<arr.size();i++){ System.out.println(arr.get(i).name+"\t"+arr.get(i).age); } } public static void suiji(){ Random r = new Random(); int num = r.nextInt(9); ArrayList<Stu> arr = new ArrayList<Stu>(); Stu s0 = new Stu(); s0.name = "董斌"; s0.age = 20; Stu s1 = new Stu(); s1.name = "张锐"; s1.age = 21; Stu s2 = new Stu(); s2.name = "王荣臣"; s2.age = 22; Stu s3 = new Stu(); s3.name = "韩凯"; s3.age = 23; Stu s4 = new Stu(); s4.name = "张禄"; s4.age = 24; Stu s5 = new Stu(); s5.name = "刘继勋"; s5.age = 25; Stu s6 = new Stu(); s6.name = "张维"; s6.age = 26; Stu s7 = new Stu(); s7.name = "牛攀"; s7.age = 28; Stu s8 = new Stu(); s8.name = "魏中豪"; s8.age = 29; arr.add(s0); arr.add(s1); arr.add(s2); arr.add(s3); arr.add(s4); arr.add(s5); arr.add(s6); arr.add(s7); arr.add(s8); System.out.println(arr.get(num).name+"\t"+arr.get(num).age); }
//ArrayList集合编写库存系统
public static void cz(){ while(true){ switch (xz()) { case 1:show(); break; case 2:xg(); break; case 3: return; default: System.out.println("输入有误"); break; } } } public static int xz(){ System.out.println("1、查看商品库存"); System.out.println("2、修改库存数量"); System.out.println("3、退出"); System.out.println("输入操作编号"); System.out.println("-----------------------------"); Scanner sc = new Scanner(System.in); int num = sc.nextInt(); return num; } public static void show(){ ArrayList<Product> arr = new ArrayList<Product>(); Product p0 = new Product(); p0.name = "MackBookAir"; p0.price = 6988.88; p0.size = 13.3; p0.count = 5; arr.add(p0); Product p1 = new Product(); p1.name = "ThinkpadT450"; p1.price = 5999.99; p1.size = 14.0; p1.count = 10; arr.add(p1); Product p2 = new Product(); p2.name = "ASUS-FL5800"; p2.price = 4999.5; p2.size = 15.6; p2.count = 18; arr.add(p2); System.out.println("----------------------商城库存清单--------------------"); System.out.println("品牌型号\t尺寸\t价格\t库存数"); int csum = 0; for(int i=0;i<arr.size();i++){ System.out.println(arr.get(i).name+"\t"+arr.get(i).size+"\t"+arr.get(i).price+"\t"+arr.get(i).count); csum = csum + arr.get(i).count; } System.out.println("库存数\t"+csum); System.out.println("---------------123------------------"); } public static void xg(){ ArrayList<Product> arr = new ArrayList<Product>(); Product p0 = new Product(); p0.name = "MackBookAir"; p0.price = 6988.88; p0.size = 13.3; p0.count = 5; arr.add(p0); Product p1 = new Product(); p1.name = "ThinkpadT450"; p1.price = 5999.99; p1.size = 14.0; p1.count = 10; arr.add(p1); Product p2 = new Product(); p2.name = "ASUS-FL5800"; p2.price = 4999.5; p2.size = 15.6; p2.count = 18; arr.add(p2); System.out.println("商品编号"+"品牌型号\t尺寸\t价格\t库存数"); for(int i=0;i<arr.size();i++){ System.out.println(i+"\t"+arr.get(i).name+"\t"+arr.get(i).size+"\t"+arr.get(i).price+"\t"+arr.get(i).count); } System.out.println("----------------------------------------------------"); Scanner sc = new Scanner(System.in); System.out.println("输入编号"); int num = sc.nextInt(); System.out.println("输入数量"); int n = sc.nextInt(); arr.get(num).count = n; } public static void sj(){ ArrayList<Pho> arr = new ArrayList<Pho>(); Pho p0 = new Pho(); p0.brand = "小米"; p0.price = 1999.0; p0.color = "blue"; arr.add(p0); Pho p1 = new Pho(); p1.brand = "华为"; p1.price = 3999.0; p1.color = "white"; arr.add(p1); Pho p2 = new Pho(); p2.brand = "乐视"; p2.price = 999.0; p2.color = "black"; arr.add(p2); Pho p3 = new Pho(); p3.brand = "奇酷"; p3.price = 2999; p3.color = "red"; arr.add(p3); for(int i = 0;i<arr.size();i++){ System.out.println(arr.get(i).brand+"\t"+arr.get(i).price+"\t"+arr.get(i).color); } } public static void yg(){ ArrayList<Employee> arr = new ArrayList<Employee>(); Employee e0 = new Employee(); e0.name = "张三"; e0.num = 10; e0.salary = 3000; arr.add(e0); Employee e1 = new Employee(); e1.name = "李四"; e1.num = 20; e1.salary = 4000; arr.add(e1); Employee e2 = new Employee(); e2.name = "王五"; e2.num = 30; e2.salary = 5000; arr.add(e2); for(int i = 0;i<arr.size();i++){ System.out.println(arr.get(i).name+"\t"+arr.get(i).num+"\t"+arr.get(i).salary); } } //简述自定义数据类型的定义格式和使用方式? //创建java文件,与类名相同 //public class 类名{ //数据类型 属性名称1; // 数据类型 属性名称2; //// } //导包:我们将所有的类放到同一个文件夹下,可以避免导包。 // 创建对象:数据类型 变量名 = new 数据类型(); //调用方法:目前我们定义的自定义类不涉及方法,只是属性(自定义类中的方法部分在面向对象部分讲解) // 访问属性:变量名.属性 //简述ArrayList集合的定义格式和常用方法的功能? //导包:import java.util.ArrayList; // 创建对象:与其他普通的引用数据类型创建方式完全相同,但是要指定容器中存储的数据类型: // ArrayList<要存储元素的数据类型> 变量名 = new ArrayList<要存储元素的数据类型>(); //arr.add(); // arr.get(); // arr.size(); // arr.set(); // arr.remove(); // arr.clear(); }

 

ArrayList集合的使用

标签:自定义数据类型   格式   引用   操作   print   switch   opp   csu   can   

原文地址:https://www.cnblogs.com/yelena-niu/p/9042311.html

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