本示例的FOR循環創建一個Mandelbrot圖像。 

復制代碼代碼如下:

using System; 
namespace a 
{ 
class Program 
{ 
public static void Main(string[] args) 
{ 
double realCoord,imagCoord; 
double realTemp,imagTemp,realTemp2,arg; 
int iterations; 
for (imagCoord=1.2;imagCoord>=-1.2;imagCoord-=0.05) 
{ 
for(realCoord=-0.6;realCoord<=1.77;realCoord+=0.03) 
{ 
iterations=0; 
realTemp=realCoord; 
imagTemp=imagCoord; 
arg=(realCoord*realCoord)+(imagCoord*imagCoord); 
while((arg<4)&&(iterations<40)) 
{ 
realTemp2=(realTemp*realTemp)-(imagTemp*imagTemp)-realCoord; 
imagTemp=(2*realTemp*imagTemp)-imagCoord; 
realTemp=realTemp2; 
arg=(realTemp*realTemp)+(imagTemp*imagTemp); 
iterations+=1; 
} 
switch (iterations % 4) 
{ 
case 0: 
Console.Write("."); 
break; 
case 1: 
Console.Write("o"); 
break; 
case 2: 
Console.Write("0"); 
break; 
case 3: 
Console.Write("@"); 
break; 
} 
} 
Console.Write("n"); 
} 
Console.ReadKey(); 
} 
} 
} 

循環結構之DO語句 
循環結構之DO語句，根據布爾值的測試結果，執行相應代碼，DO語句至少執行一次。 

復制代碼代碼如下:

using System; 
namespace a 
{ 
class Program 
{ 
public static void Main(string[] args) 
{ 
double balance,interestRate,targetBalance; 
Console.WriteLine("What is your current balance?"); 
balance=Convert.ToDouble(Console.ReadLine()); 
Console.WriteLine("What is your current annual interest rate (in %)?"); 
interestRate= 1+Convert.ToDouble(Console.ReadLine())/100.0; 
Console.WriteLine("What balance would you like to have?"); 
targetBalance=Convert.ToDouble(Console.ReadLine()); 
int totalYears=0; 
do 
{ 
balance*=interestRate; 
++totalYears; 
} 
while(balance<targetBalance); 
Console.WriteLine("In {0} year {1} you'll have a balance of {2}.",totalYears,totalYears==1?"":"s",balan00ce); 
Console.ReadKey(); 
} 
} 
} 

總結 
DO語句在循環時不管條件是否成立它至少執行一次,頁for循環語句如果條件不成立一次不執行了。