数组是一种包含若干变量的数据结构,这些变量都可以通过计算索引进行访问。数组中的数组的元素具有相同的类型。
数组有一个“秩”。数组的秩又称为数组的维度。“秩”为 1 的数组称为一维数组。“秩”大于 1 的数组称为多维数组。维度大小确定的多维数组通常称为两维数组、三维数组等。
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
声明数组
声明数组时,方括号 ([]) 必须跟在类型后面,而不是标识符后面。在 C# 中,将方括号放在标识符后是不合法的语法。
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
C# 支持一维数组、多维数组(矩形数组)和数组的数组(交错的数组)。
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
一维数组:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
int[] arrayname;
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
多维数组:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
int[,] arrayname;
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
数组的数组(交错的):
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
int[][] arrayname ;
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
声明数组并不实际创建它们。在 C# 中,数组是对象,必须进行实例化。
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
示例:
using System;
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
class TestArray
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
{
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
public static void Main()
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
//声明一个整型一维数组的引用,变且在堆中分配连续5个整型变量的空间。
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
int[] numbers = new int[5];
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
// 声明一个二维字符串数组的引用
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
string[,] names = new string[5,4];
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
// 数组的数组,相当声明了包含5个byte型一维数组的引用变量的一维数组长度为5
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
byte[][] scores = new byte[5][];
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
//为每个btye型一维数组实例化
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
for (int i = 0; i < scores.Length; i++)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
scores[i] = new byte[i+3]; //非矩形的
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
}
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
for (int i = 0; i < scores.Length; i++)
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedSubBlockStart.gif)
{
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
Console.WriteLine("Length of row {0} is {1}", i, scores[i].Length);
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
}
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
}
![](https://www.cnblogs.com/Images/OutliningIndicators/InBlock.gif)
}
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
初始化数组
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
C# 通过将初始值括在大括号 (
{}) 内为在声明时初始化数组提供了简单而直接了当的方法。下面的示例展示初始化不同类型的数组的各种方法。
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
一维数组
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[] numbers = new int[5]
{1, 2, 3, 4, 5};
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[] names = new string[3]
{"Matt", "Joanne", "Robert"};
可省略数组的大小,如下所示:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[] numbers = new int[]
{1, 2, 3, 4, 5};
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[] names = new string[]
{"Matt", "Joanne", "Robert"};
如果提供了初始值设定项,则还可以省略 new 运算符,如下所示:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[] numbers =
{1, 2, 3, 4, 5};
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[] names =
{"Matt", "Joanne", "Robert"};
多维数组
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[,] numbers = new int[3, 2]
{
{1, 2},
{3, 4},
{5, 6} };
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[,] siblings = new string[2, 2]
{
{"Mike","Amy"},
{"Mary","Albert"} };
可省略数组的大小,如下所示:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[,] numbers = new int[,]
{
{1, 2},
{3, 4},
{5, 6} };
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[,] siblings = new string[,]
{
{"Mike","Amy"},
{"Mary","Albert"} };
如果提供了初始值设定项,则还可以省略 new 运算符,如下所示:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[,] numbers =
{
{1, 2},
{3, 4},
{5, 6} };
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
string[,] siblings =
{
{"Mike", "Amy"},
{"Mary", "Albert"} };
交错的数组(数组的数组)
可以像下例所示那样初始化交错的数组:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[][] numbers = new int[2][]
{ new int[]
{2,3,4}, new int[]
{5,6,7,8,9} };
可省略第一个数组的大小,如下所示:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[][] numbers = new int[][]
{ new int[]
{2,3,4}, new int[]
{5,6,7,8,9} };
-或-
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[][] numbers =
{ new int[]
{2,3,4}, new int[]
{5,6,7,8,9} };
访问数组成员
访问数组成员可以直接进行,类似于在 C/C++ 中访问数组成员。例如,下面的代码创建一个名为 numbers 的数组,然后向该数组的第五个元素赋以 5:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[] numbers =
{10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0};
numbers[4] = 5;
下面的代码声明一个多维数组,并向位于 [1, 1] 的成员赋以 5:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[,] numbers =
{
{1, 2},
{3, 4},
{5, 6},
{7, 8},
{9, 10} };
numbers[1, 1] = 5;
下面声明一个一维交错数组,它包含两个元素。第一个元素是两个整数的数组,第二个元素是三个整数的数组:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[][] numbers = new int[][]
{ new int[]
{1, 2}, new int[]
{3, 4, 5}
};
下面的语句向第一个数组的第一个元素赋以 58,向第二个数组的第二个元素赋以 667:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
numbers[0][0] = 58;
numbers[1][1] = 667;
对数组使用 foreach
C# 还提供 foreach 语句。该语句提供一种简单、明了的方法来循环访问数组的元素。例如,下面的代码创建一个名为 numbers 的数组,并用 foreach 语句循环访问该数组:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[] numbers =
{4, 5, 6, 1, 2, 3, -2, -1, 0};
foreach (int i in numbers)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
{
System.Console.WriteLine(i);
}
由于有了多维数组,可以使用相同方法来循环访问元素,例如:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
int[,] numbers = new int[3, 2]
{
{9, 99},
{3, 33},
{5, 55}};
foreach(int i in numbers)
![](https://www.cnblogs.com/Images/OutliningIndicators/ExpandedBlockStart.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/ContractedBlock.gif)
{
Console.Write("{0} ", i);
}
该示例的输出为:
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
9 99 3 33 5 55
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
posted @
2007-06-30 00:40
wenanry
阅读(
326)
评论()
编辑
收藏
举报