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);

}

}

}

}