C#笔记—关于数组和集合类

数组和集合类的主要差异：

1.数组需要声明它所容纳的元素的类型，而集合则不需要。原因：集合是以object的形式来存储它所容纳的元素的。

2.数组的实例具有固定的大小，不能随意增大或缩小。而集合可根据需要动态改变大小。

3.数组可以是多维的，但集合是线性的。（集合可以嵌套，其元素可以是其他集合，这样我们可以模拟一个多维数组，但是会影响程序的可读性）。

下面是常用的五个集合类的示例{（ArrayList、Queue、Stack、Hashtable、SortedList)，（引自Visual C#2008 从入门到精通）：

 

C# Code:

  using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Collections;

namespace AssembleClass
{
    class Program
    {
        static void Main(string[] args)
        {

            //1. ArrayList
            /*ArrayList numbers = new ArrayList();
            foreach (int number in new int[12] { 10, 9, 8, 7, 7, 6, 5, 10, 4, 3, 2, 1 })
            {
                numbers.Add(number);

            }
            numbers.Insert(numbers.Count - 1, 99);

            numbers.Remove(7);
            numbers.RemoveAt(6);

            for (int i = 0; i < numbers.Count; i++)
            {
                int number = (int)numbers[i];
                Console.WriteLine(number);

            }

            foreach (int number in numbers)
            {
                Console.WriteLine(number);

            }*/

 

            //2. Queue
            /*Queue numbers = new Queue();

            foreach(int number in new int[4]{9,3,7,2})
            {
                numbers.Enqueue(number);
                Console.WriteLine(number+" has joined the queue");

            }

            foreach(int number in numbers)
            {
               Console.WriteLine(number);

            }

            while(numbers.Count>0)
            {
                int number =(int)numbers.Dequeue();
                Console.WriteLine(number+" has left the queue");

            }*/

 

            //3. Stack
            /*Stack numbers = new Stack();

            foreach(int number in new int[4] {9,3,7,2})
            {
                numbers.Push(number);
                Console.WriteLine(number+" has been pushed on the stack");

            }

            foreach (int number in numbers)
            {
                Console.WriteLine(number);
               
            }

            while (numbers.Count>0)
            {
                int number=(int)numbers.Pop();
                Console.WriteLine(number+" has been popped off the stack");

            }*/

            //4. Hashtable
            /*Hashtable ages = new Hashtable();
            ages["John"] = 42;
            ages["Diana"] = 43;
            ages["James"] = 15;
            ages["Francesca"] = 13;

            foreach (DictionaryEntry element in ages)
            {
                string name = (string)element.Key;
                int age = (int)element.Value;
                Console.WriteLine("Name:{0},Age:{1}",name,age);

            }*/

            //5. SortedList
            SortedList ages =new SortedList();

            ages["John"] = 42;
            ages["Diana"] = 43;
            ages["James"] = 15;
            ages["Francesca"] = 13;

            foreach (DictionaryEntry element in ages)
            {
                string name = (string)element.Key;
                int age = (int)element.Value;
                Console.WriteLine("Name:{0},age:{1}", name, age);

      }

           }

  }
  
}