C# Week3_3

10/02/2010 (wed)

 
 

switch

int i=2

switch(i)

{

case　1:

case　2: Console.WriteLine("Hello");

break;

}

If case1 uses without break and no statement sequence, it will work.

 
 

for()

 
 

for(); = for() {}

*Using ";" after for, it means sentence end.

 
 

for(int i=10,j=12; i<0; i++,j--) {}

 
 

increment operator

pre increment ++i = i+1

post increment i++ = i+1

Both are same meaning, but increment timing is different.

ex1

int i=5;

int j=i++ +6;

 
 

Result 11

ex2

int i=5;

int j=++i +6;

 

Result 12

ex3

int i=5;

int j=++i - --i + i++;

Console.WriteLine(i);

Console.WriteLIne(j);

 
 

Result 6(i)

6(j)

ex4

int i=10;

int j=5;

int k=i-- - --i * --j + j++ / i++;

Console.WriteLine(i);

Console.WriteLine(j);

Console.WriteLine(k);

 
 

Result

9(i)

5(j)

-22(k)

k=10-8*4+4/8

=10-32+0

=-22

 
 

for : We know how many times it works for loop.

while : We don't know how many times it works for loop.

do while : At least one time.

 
 

whille(bool condition)

{

Console.WriteLine(" ");

}

 
 

do

{

Console.WriteLine(" ");

} while(bool condition);

 
 

string value=Console.Readline();

It means to read someone to input value.

int i=int.Parse(value);

It means to cast from string to integer.

 
 

Lotto example

Console.WriteLine("Enter number between 1 and 100");

string number = Console.ReadLine();

int num = int.Parse(number);

while (num != 50)

{

Console.WriteLine("Sorry you missed chance");

Console.WriteLine("Please enter 1 if you want play again otherwise enter 0");

string choice = Console.ReadLine();

int value = int.Parse(choice);

if (value == 0)

{

Console.WriteLine("Good bye");

break;

}

else

{

Console.WriteLine("Enter any number between 1 and 100");

string number1 = Console.ReadLine();

int num1 = int.Parse(number1);

if (num1 == 50)

{

Console.WriteLine("congratulation you won prises of 200,000 dollar");

break;

}

}

}

 

if (num == 50)

{

Console.WriteLine("congratulation you won prises of 200,000 dollar");

}