Dhanushka's Web Blog

all the programming languages have some kind of a machanism to store progrmatic data in c# there are two types called reference types and value types when we consider value types almost all the programming languages had implemented them as a part of their framework

Basically their are two types of value types 

static

dynamic

type of the variables are known in cmpile time this is the common practice in languages like c#, java, c, c++

int a=10;

string name="Dhanushka Sandaruwan Athukorala";

here the variable comes with some kind of a tag that contains it type. when you assign a value to the variable at the run time this tag value is set to the type of this assigned value

the funny thing is every time an operation is performed the type will be checked to make sure that the operation is safe

for an example this will wok in dynamically typed code but not in static typing

a="Dhanushka Sandaruwan Athukorala";

if(true)

{

a=12;

}

b=a/2;

here as you can see when the devission occur a's type tag is set to int rather than string thats the magic of dynamic typing

now lets see what c# 3.0 offeres

var fullName="Dhanushka Sandaruwan Athukorala";

var age=22;

var arr=new[] {1, 2, 3, 4}

hmm...

what's going on

at first you would say that "var" is just a new value type!!!

No sir!!! its not!!!

its just a new keyword introduced in c# 3.0 to indicate to the compiler that "i'm gona create a new variable, but i dont know about its type. so you just take care of it for me!!"

we all know that c# is a staticstically typed language, but yet it si offering a functionallity similar to a dynamically typed one???

whats the secret??

what happens here is a newly written type inferencing algorithm is used by the compiler(take this to note, which means this happens at compile time not at run time) goes through the code and finds out what's the type of the variables assigned to the "var" variables. which means that this is similar to an explicit declaration of a variable but you dont have to know the type of it.

for an instance if we referfullName.GetType()  and age.GetType() values at run time they will give string and int32 as their variable types

but their are some other issues you should be aware of when you use var 

you must  initialize a variable with a nonnull value when you declare it

this want compile

var a; var b=null;

a=18;

as a conclusion we can say although this will distance c# from being a simple language, it will enhance the developer productivity as well as code readability. 

for a start there are two types of arrays in c#

1) rectangular arrays

2) jagged arrays

rectangular arrays are of course rectangular arrays :-) wether single dimensional or multi dimensional all their elements length are equal

e.g

jagged arrays are just arrays of arrays but when it comes to their shape their element length can vary

A question i always get from my freinds, specially java guys:-)

the answer is not yet (not in C# 3.0) but there are some ways to get around it

although c# doesnt support mulitple inheritance it does support muliple implementation. which means that in c# you can implement more than 1 interface.

let's try it out

lets say we want a class to have the functionalities of a vehicle, and this class will represent a 4 wheel vehicle lets name this class as myCar

what we have to do now is we have to create two interfaces called IVehicle and I4Wheel

As the name indicate its a puzzle game developed for windows mobile using c# and .net compact framework 2.0

The game contains 15 numbered blocks with a single empty space which acts as a slider space for number swap

Game concept

a number set containing numbers ranging from 1 to  15 is randomly arranged using a random number generator depending on the users difficulty level

What the players have to do is rearrange them within a fixed number of moves and within a selected time frame

What make it stand out from other puzzle games

the game provide some  advance game play features like hints, autoplay... etc

and if  you are a player who choose user interfacer features over advanced algorithms, then thhis game is for you

Hint for the next move and animated autoplay

All the player moves will be taken in to account for both hint and autoplay facilities

Depending on the moves history the most efficient next move will be predicted and is shiwn to the players as a blinking number

The autoplay facility also uses an algorithm which takes the dynamically changing player moves history in to account for predicting the most efficient autoplay move Set

the game also conntains facilities like takeback (lets the users undo any number of  moves), reset initial state (lets the user to restart from the beginning), resume  play (depending on the game exit status the  players can resume from where they left off or start a new game)

if that's not enough  the game also comes with a rich set of sweet animations which will enhance the users game ay experience

all yo have to do is 

1)drag an drop a timer from the tool box

2)go to properties of the timer

3)set the intervel to the number of miliseconds you want to raise the tick event

4)select the Tick event and double click it

an event handler will get creteated automatically

add the following code inside it's body