Add, delete, traverse and find elements of ArrayList class

Topic description  

Add, delete, traverse and find elements of the ArrayList class. (console application)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;//Add namespace


Addition of namespace ArrayList class elements
{
    class Program
    {
        static void Main(string[] args)
        {
            ArrayList  myArrayList=new ArrayList(5);
            //The advantage of ArrayList is that the length is not fixed and the type is arbitrary
            //The length of the array is fixed and cannot be changed. The type is single and can only be one of them
            Console.WriteLine("myArrayList has {0} elements after initialization", myArrayList.Count);
            //Add method is used to add a single element to the ArrayList, only one can be added at a time
            myArrayList.Add(123);
            myArrayList.Add('a');
            myArrayList.Add("myArrayList");
            myArrayList.Add(25.6);
            myArrayList.Add(10L);
            Console.WriteLine("After adding 5 personal elements using the Add method, there are {0} elements", myArrayList.Count);
            //AddRange(myArrayList) method is used to add multiple elements to ArrayList at one time, which can be an array
            string[] mystringArray = { "Zhang San", "Li Si", "Wang Wu" , "Zhao Liu"};
            myArrayList.AddRange(mystringArray);
            Console.WriteLine("After using the AddRange method, there are {0} elements",myArrayList.Count);
            // loop through the collection elements
            //The reference type string\object class is the base class of all types
            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;//Add namespace


Deletion of namespace ArrayList class elements
{
    class Program
    {
        static void Main(string[] args)
        {
            //There are four ways to delete elements
            ArrayList myarrayList = new ArrayList(3);
            myarrayList.Add(1);
            myarrayList.Add("成功");
            myarrayList.Add(25.6);
            string [] mystringArray={"Zhang San", "Li Si", "Wang Wu", "Zhao Liu"};
            myarrayList.AddRange(mystringArray);
            Console.WriteLine("Delete previous content: ");
            foreach(object outelement in myarrayList)
                Console.Write(outelement+"\t");
            Console.WriteLine();
            //Remove(value)
            Console.WriteLine("Delete the content");
            myarrayList.Remove("张三");
            foreach (object outelement in myarrayList)
                Console.Write(outelement + "\t");
            Console.WriteLine();
            //RemoveAt(index value)
            Console.WriteLine("Delete the value after Li Si");
            myarrayList.RemoveAt(3);
            foreach (object outelement in myarrayList)
                Console.Write(outelement + "\t");
            Console.WriteLine();
            //RemoveRange (starting index, number to delete)
            Console.WriteLine("Delete the value after Wang Wu and Zhao Liu: ");
            myarrayList.RemoveRange(3, 2);
            foreach (object outelement in myarrayList)
                Console.Write(outelement + "\t");
            Console.WriteLine();
            //Clear() clears all elements
            Console.WriteLine("Clear all elements: ");
            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;//Add namespace


namespace ArrayList class element traversal and search
{
    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("String:");
            string[] mystringArray = { "Zhang San", "Li Si", "Wang Wu", "Zhao Liu" };
            myArrayList.AddRange(mystringArray);
            foreach (object outelement in myArrayList)
                Console.Write(outelement + "\t");
            // find element
            //There are three methods
            //IndexOf (the element to find), returns an index value of the first occurrence, or -1 if it does not exist
            Console.WriteLine(myArrayList.IndexOf("张三"));
            //LastIndexOf (the element to find), returns an index value of the last occurrence, or -1 if it does not exist
            Console.WriteLine(myArrayList.LastIndexOf(20));
            //BinarySearch(), the type is inconsistent, sometimes an error is reported
            Console.WriteLine(myArrayList.BinarySearch(2));
        }
    }
}