流程控制
8、if….else語句
using System;
using System.Collections.Generic;
using System.Text;
//if...else選擇語句
namespace IfElseTest
{
class IfElseTest
{
static void Main(string[] args)
{
bool flagCheck = true;
if (flagCheck == true)
{
Console.WriteLine("The flag is set to true.");
}
else
{
Console.WriteLine("The flag is set to false.");
}
}
}
}
9、switch語句
using System;
using System.Collections.Generic;
using System.Text;
//switch語句
namespace SwitchTest
{
class SwitchTest
{
static void Main(string[] args)
{
int caseSwitch = 1;
switch (caseSwitch)
{
case 1:
Console.WriteLine("Case 1");
break;
case 2:
Console.WriteLine("Case 2");
break;
default:
Console.WriteLine("Default case");
break;
}
}
}
}
10、for循環語句
using System;
using System.Collections.Generic;
using System.Text;
//for循環語句
namespace ForLoopTest
{
class ForLoopTest
{
static void Main(string[] args)
{
for (int i = 1; i <= 5; i++)
{
Console.WriteLine(i);
}
}
}
}
11、while循環語句
using System;
using System.Collections.Generic;
using System.Text;
//while循環語句
namespace WhileText
{
class WhileTest
{
static void Main(string[] args)
{
int n = 1;
while (n < 6)
{
Console.WriteLine("Current value of n is {0}", n);
n++;
}
}
}
}
12、do…while循環語句
using System;
using System.Collections.Generic;
using System.Text;
//do...while循環語句
namespace TestDoWhile
{
class TestDoWhile
{
static void Main(string[] args)
{
int x = 0;
do
{
Console.WriteLine(x);
x++;
}
while (x < 5);
}
}
}
13、foreach語句
using System;
using System.Collections.Generic;
using System.Text;
//foreach語句
namespace ForeachTest
{
class ForeachTest
{
static void Main(string[] args)
{
int[] fibarray = new int[] { 0, 1, 2, 3, 5, 8, 13 };
foreach (int i in fibarray)
{
Console.WriteLine(i);
}
}
}
}
14、throw語句
using System;
using System.Collections.Generic;
using System.Text;
//throw語句
namespace ThrowTest
{
class ThrowTest
{
static void Main(string[] args)
{
string s = null;
if (s == null)
{
throw new ArgumentNullException();
}
Console.Write("The string is null.");
}
}
}
15、try…catch語句
using System;
using System.Collections.Generic;
using System.Text;
//try...catch語句,try塊包含對可能導致異常的MyMethod()方法的調用。
//catch子句包含僅在屏幕上顯示消息的異常處理程序。
//當從MyMethod()內部調用throw語句時，系統查找catch語句並顯示Exception caught消息。
namespace TrycatchTest
{
class TrycatchTest
{
static void Main(string[] args)
{
try
{
string s = null;
ProcessString(s);
}
catch (Exception e)
{
Console.WriteLine("{0} Exception caught.", e);
}
}
static void ProcessString(string s)
{
if (s == null)
{
throw new ArgumentNullException();
}
}
}
}
16、try…finally語句
using System;
using System.Collections.Generic;
using System.Text;
//try...finally語句，代碼中有一個導致異常的無效轉換語句，當程序運行時，將產生一條運行時錯誤信息，
//但程序沒有去處理異常信息，而是控制傳遞給finally子句繼續執行並顯示輸出。
namespace TryFinallyTest
{
class TryFinallyTest
{
static void Main(string[] args)
{
int i = 123;
string s = "Some string";
object o = s;
try
{
i = (int)o;//包含一個字符串，無法轉換爲int類型
}
finally
{
Console.Write("i={0}", i);
}
}
}
}
17、try…catch…finally語句
using System;
using System.Collections.Generic;
using System.Text;
//try...catch...finally語句，代碼演示了捕捉異常，並作出相應處理。
namespace TryCatchFinallyTest
{
class TryCatchFinallyTest
{
static void Main(string[] args)
{
try
{
Console.WriteLine("Executing the try statement.");
throw new NullReferenceException();
}
catch (NullReferenceException e)
{
Console.WriteLine("{0} Caught exception #1.", e);
}
catch
{
Console.WriteLine("Caught exception #2.");
}
finally
{
Console.WriteLine("Executing finally block.");
}
}
}
}