ArrayList集合的使用
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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 = "男"; 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(); }
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