1. 2. C# Language Fundamentals
Data Types
Numeric Types
Non-Numeric Types: char and bool
Variables
Definite Assignment
Constants
Strings
Statements
Code Samples

2. Data Types Common C# intrinsic data types Type Size in Bytes byte 1
bool 2
int 4
long 8
float
double
decimal 12

3. Typing in C# C# is a strongly typed language
Types come in two flavours
Value (intrinsic)
Reference (classes …)
Each type has a name (int) and size (4b)
The .Net equivalents for int is Int32

4. Numeric Data Types Unsigned (positive) Signed (positive or negative)
byte, ushort, uint, ulong
Signed (positive or negative)
short, int, long, float, decimal, double
Select the smallest type that will hold the required range of numbers

5. Non-Numeric Types: char and bool
Holds just a single character
Can hold:
Simple character (‘A’)
Unicode character (u\0041)
Escape character (‘\n’)
bool
Holds true or false in one byte

6. Declaring Local Variables
int myInt;
System.Console.WriteLine("Uninitialized, myInt: {0}",myInt);
myInt = 5;
int mySecondInt = 10; // declare and initialise
int myInt4,myInt5; // declare multiple variables
What is the value on an integer before it is initialised?

7. Declaring Constants Why would you create constants?
const int FreezingPoint = 32; // degrees Farenheit
const int BoilingPoint = 212;
Why would you create constants?

8. Declaring Enumerations
An enumeration is a set of named constants
// declare the enumeration
enum Temperatures:int {
WickedCold = 0,
FreezingPoint = 32,
LightJacketWeather = 60,
SwimmingWeather = 72,
BoilingPoint = 212, }
The data type defaults to int
Why would you create enumerations?

9. Using Enumerations
System.Console.WriteLine("Freezing point of water: {0}",
(int) Temperatures.FreezingPoint );
System.Console.WriteLine("Boiling point of water: {0}",
(int) Temperatures.BoilingPoint );

10. Declaring Strings A string is an object
string myString = “Hello World” ;// declare and initialise string
Where would you use strings
in your code?

11. Statements, Expressions & White Space
A statement ends in a semicolon
int myInt = 23;
An expression can be part of an assignment
myInt = myInt * 23;
White spaces are ignored
myInt = myInt * ;

12. Unit 2 Lab To write statements that prompt and greet the user
1. Open Visual Studio.Net and create a new C# Console Application project
2. In the Main method insert the following line:
string myName;
3. Write a statement that prompts users for their name.
4. Write another statement that reads the user’s response from the keyboard and assigns it to the myName string.
5. Add one more statement that prints “Hello myName” to the screen (where myName is the name the user typed in).
6. Save your work.

13. Unit 2 Lab …
When completed, the Main method should contain the following:
static void Main( ) {
string myName;
Console.WriteLine("Please enter your name");
myName = Console.ReadLine( );
Console.WriteLine("Hello {0}", myName); }