Variables

Every variable has a type that determines what values can be stored in it:

• Non-nullable value type
• Nullable value type
• object
• Class type, Interface type, Array type, Delegate type

Identifiers

Identifiers are variable names.
Identifiers start with a letter or _ and use PascalCase.
@identifier allows for variables to be named with C# reserved words.

Creating

C# is strongly typed, so all variables need to be typed:

type identifier; // Declare a variable.
type identifier = value;	// Declare and initialize (instantiate).

Implicit Typing

Implicitly typed local variables are created with var:

var message = "Hello, world!";	// message is now implicitly typed string.

The var keyword requires the variable to be declared and initialized.

Uses

The var keyword can be used:

• On local variables declared at method scope
• In a for initialization statement.
• in a foreach initialization statement.
• In a using statement.