C# Data Types - Online Resource

Data Types

C#	VB.Net	Type	Suffix	Comments
bool	Boolean	System.Boolean		(1 bit) true or false
byte	Byte	System.Byte		(8 bits) Unsigned Integer 0 to 255
char	Char	System.Char		(16 bits) Unicode character (0 to 65536 different characters) \u 000 to \u FFFF
n/a	Date	System.DateTime		- Jan 1 100 to Dec 31 9999
decimal	Decimal	System.Decimal	m or M (D in VB.Net)	(96 bits) Precise fractional or integral type that can represent decimal numbers with 29 significant digits 1 E -28 to 7.9 E 28 Currency in VBA
double	Double	System.Double	d or D (R in VB.Net)	(64 bits) Double Precision Floating Point -1.797 E 308 to 1..797 E 308
float	Single	System.Single	f or F	(32 bits) Single Precision Floating Point -3.402 E 38 to 3.4.02 E 38
int	Integer	System.Int32		(32 bits) -2147483648 to 2147483647
long	Long	System.Int64	l or L	(64 bits) -9.2 E 18 to 9.2 E 18
object	Object	System.Object		Reference Type
sbyte	n/a	System.SByte		(16 bits) -128 to 127
short	Short	System.Int16		(16 bits) -32,768 to 32,767 Integer in VBA
string	String	System.String		Reference Type
uint	n/a	System.UInt32	u or U	(32 bits) Unsigned Integer 0 to 4,294,967,295
ulong	n/a	System.UInt64	ul or UL	Unsigned Integer 0 to 1.84 E 19
ushort	n/a	System.UInt16		Unsigned Integer 0 to 65535
System.Tuple		System.Tuple

Integers use modulo arithmetic, so no overflow can occur
The default value type for any literal is "int"

Division follows standard "integer division" rules when using integer types
Division by zero causes an exception for integer types (DivideByZeroException)
Division by zero results in infinity for floating point types

int a = 7 
int b = 2 
int c = a/b  ' c=3 not 3.5

float d = 4 
float e = 3 
float f = d/e  ' f = 1.33333

float g = 1.0F / 0.0F   ' g=positive infinity  
float h = -1.0 / 0.0    ' h=negativeinifnity  
float j = 0.0F / 0.0F   ' j = NaN

Wrapping - No Overflow

int a = 2147483647; 
int b = 1; 
int sum = a + b; 
'wraps to sum = -2147483648

???

Intrinsic vs User Defined - intrinsic are built-in
It is always best to use the datatype that uses the smallest amount of space (i.e. bytes) yet can still handle all the data assigned to it. The smaller the bytes the faster it executes.
You should use the datatype conversion functions instead of using the Val() function when you want to convert from one datatype to another.

Boxing - Forcing value types to act as reference types
Casting - Converting objects of one type into another type

Casting can either be narrowing or widening

Dynamic Types

VB	C#
If (myObject IsNot Nothing) Then	If (!myObject.Equals(null))
End If	{
	}

TypeName(x)	x.GetType.ToString();

GetType(Integer)	typeof(int);

nothing	null

DateTime is not a built-in C# type

Initialising

VB	C#
Dim b As Byte = &H2A 'hex	byte o = 0x2A;
Dim o As Byte = &O52 'octal
Dim ed As Date = #12/31/2007 12:15:00 PM#
Dim amount As Decimal = 23.99@	decimal amount = 23.99m;
Dim number As Single = 2.9!	float number = 2.9f;
Dim total As Long = 23432L

System.Convert.ToInt16(sNumber) 
System.Convert.ToDouble(sNumber)

Type.GetTypeCode()     = TypeCode.String

Decimal instead of Currency

The Currency datatype in VBA has been replaced with the Decimal datatype in VB.NET.
In most cases these will be interchangeable however they do actually differ in their precision.
The Decimal datatype in .NET is more accurate than the VBA Currency datatype
The Decimal datatype is a fixed-precision of the decimal point.
Decimal values require the suffix "m" or "M".
You can force a datatype to a literal value to Decinal by adding "D" to the end of the literal value. For example 2344534D is forced to be interpreted as a Decimal, without the "D" the literal value is interpreted as a Long.

User Defined Data Types

You define custom datatypes outside of procedures at the top of your module. Once you have created your type use the Dim statement to declare a variable of that type.

This method allows you to define an object that encapsulates and validates its own data.
Remember: An object variable declared "As New" contains "Nothing" until the first time you refer to it in code

After you have finished with any objects you must set any refernces to it to "Nothing" in order to free the memory space & resources
Perhaps the most common is a structure to pass to an API call. You may also have to pass in parameters that are strings are finite length

Important

It is possible to create your own user defined types by usingthe "Type" statement. This is covered later
When defining a user defined type all variables within the type should be in capitals