题目描述
ArrayList类元素的添加、删除、遍历和查找。(控制台应用程序)
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections;//添加命名空间 namespace ArrayList类元素的添加 { class Program { static void Main(string[] args) { ArrayList myArrayList=new ArrayList(5); //ArrayList的好处是,长度不固定,类型随意 //数组的长度是固定的,不能更改的,类型单一,只能为其中的一种 Console.WriteLine("myArrayList初始化之后有{0}个元素",myArrayList.Count); //Add方法用于向ArrayList中添加单个元素,每次只能添加一个 myArrayList.Add(123); myArrayList.Add('a'); myArrayList.Add("myArrayList"); myArrayList.Add(25.6); myArrayList.Add(10L); Console.WriteLine("使用Add方法添加5个人元素之后,有{0}个元素",myArrayList.Count); //AddRange(myArrayList)方法用于一次性向ArrayList中添加多个元素,可以是一个数组 string[] mystringArray = { "张三", "李四", "王五" ,"赵六"}; myArrayList.AddRange(mystringArray); Console.WriteLine("使用AddRange方法后,有{0}个元素",myArrayList.Count); //遍历集合元素 //引用类型string\object类是所有类型基类 foreach(object outelement in myArrayList) Console.Write(outelement+"\t"); Console.WriteLine(); } } }
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections;//添加命名空间 namespace ArrayList类元素的删除 { class Program { static void Main(string[] args) { //元素删除有四种方法 ArrayList myarrayList = new ArrayList(3); myarrayList.Add(1); myarrayList.Add("成功"); myarrayList.Add(25.6); string [] mystringArray={"张三", "李四", "王五" ,"赵六"}; myarrayList.AddRange(mystringArray); Console.WriteLine("删除之前的内容:"); foreach(object outelement in myarrayList) Console.Write(outelement+"\t"); Console.WriteLine(); //Remove(值) Console.WriteLine("删除之后的内容"); myarrayList.Remove("张三"); foreach (object outelement in myarrayList) Console.Write(outelement + "\t"); Console.WriteLine(); //RemoveAt(索引值) Console.WriteLine("删除李四之后的值"); myarrayList.RemoveAt(3); foreach (object outelement in myarrayList) Console.Write(outelement + "\t"); Console.WriteLine(); //RemoveRange(开始的索引,要删除的个数) Console.WriteLine("删除王五、赵六之后的值:"); myarrayList.RemoveRange(3, 2); foreach (object outelement in myarrayList) Console.Write(outelement + "\t"); Console.WriteLine(); //Clear()清除所有元素 Console.WriteLine("清除所有元素:"); myarrayList.Clear(); foreach (object outelement in myarrayList) Console.Write(outelement + "\t"); Console.WriteLine(); } } }
using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Collections;//添加命名空间 namespace ArrayList类元素遍历和查找 { class Program { static void Main(string[] args) { ArrayList myArrayList = new ArrayList(2); myArrayList.Add("数字:"); int[] myintArray = { 1, 2, 3, 4, 5, 6, 7, 8, 9 }; myArrayList.AddRange(myintArray); myArrayList.Add("字符串:"); string[] mystringArray = { "张三", "李四", "王五", "赵六" }; myArrayList.AddRange(mystringArray); foreach (object outelement in myArrayList) Console.Write(outelement + "\t"); //元素的查找 //有三种方法 //IndexOf(要查找的元素),返回一个首次出现的索引值,如果不存在,返回-1 Console.WriteLine(myArrayList.IndexOf("张三")); //LastIndexOf(要查找的元素),返回一个最后一次出现的索引值,如果不存在,返回-1 Console.WriteLine(myArrayList.LastIndexOf(20)); //BinarySearch(),类型不一致,有时会报错 Console.WriteLine(myArrayList.BinarySearch(2)); } } }