The data types in c# such as string and int are actually classes in the .NET library. The language masks the connection between these data types and their c# classes, but behind the scenes they're implemented just like every other class in c#. This means variables like strings and ints have helpful built-in methods for things like converting to uppercase (ToUpper) and so on.

Type Inference (var)

The var keywork instructs the compiler to infer the type.

var message = "Hello World";

Type Casting and Conversion

Type conversions are done with the Convert class.

int x = (int)3.3;

string one = "1";
int firstNumber = Convert.ToInt32(one);

string

It is important to remember that string is a reference type, but it is immutable. That means once it has been assigned a value, it can't be altered. In C#, when methods and operators are used to modify a string, the result that is returned is actually a new string object.

Default type

A string's default type is null rather than an empty string.

Length

Property representing the length of a string.

Trim()

Removes spacing from ends of string.

ToLower()

Converts a string to lowercase.

Split()

string[] address = ipv4Input.Split(".");

int

Integral Types

sbyte and byte

short and ushort

int and uint

long and ulong

MaxValue and MinValue

Properties representing the min and max values for the type.